Classic Christianity: A Systematic Theology

5 WHETHER GOD IS TRIUNE

THE IDEA THAT THE ONE GOD MEETS US in three persons is thought to be among the most mystifying of all Christian teachings. Yet we must speak of Trinity, as Augustine knew, not because we are able to fathom it, but because we cannot keep silent on a matter so central to biblical faith (Augustine, Trin. 1.2, 3).

The mystery of God the Father, God the Son, and God the Spirit may seem to introduce a new theme into our thinking. But we have been referring to it all along, by speaking of

God as Father Almighty, the source of life, who makes Himself known in
Jesus Christ by the power of
the Spirit of God who is present throughout the historical process, working to transform it according to God’s purpose.

Thus we are not veering away from previous subjects in dealing now with the triune God, but only seeking to provide increased clarity on how the living God comes to dwell with us in broken human history.

In all Christian traditions, baptism occurs in the name of the Father, Son, and Holy Spirit. Hence Christian teaching is best thought of as a commentary on baptism. It has the happy task of trying to explain what baptism in the triune name means. This is no elective, nonobligatory task, no subordinate duty that Christian theology can either choose or refuse. For God appears constantly in the New Testament as Father, Son, and Spirit. “When I say God,” remarked Gregory Nazianzus, “I mean Father, Son, and Holy Ghost” (Orat. 33.8).

The triune confession summarizes the essentials of Christian teaching. For almost two millennia the Christian community has been using this language as a means of bringing together its most irreducible affirmations concerning God. Modern readers are urged not to reject prematurely trinitarian thinking on the wrong assumption that it amounts to worshiping three “gods”—a heresy called tritheism, consistently rejected by the classical Christian writers (Gregory of Nyssa, On “Not Three Gods”).

Salvation History in Triune Faith

The triune understanding of God gives us a way of looking at the meaning of God’s coming into the whole of history and into human hearts—the arena of God’s revelation, the subject of theology.

The simple act of baptism teaches, rehearses, and embraces the entire story of salvation. It attests to the church’s attempt to view history synoptically, to grasp a unified picture of God in acts of creation, redemption, and consummation. Classical Christianity views the history of salvation as an inclusive threefold movement from beginning to end:

It begins with an originally good creation in an undisturbed condition of human existence that plunges into the self-chosen alienation of human freedom into sin, guilt, and death.
The pivot of history is the incarnation, ministry, death, and resurrection of Jesus Christ, God’s own personal engagement in the human condition, where the Son of God speaks the Father’s Word of forgiving love to human history.
God’s own Spirit is sent in order to enable faith, hope, and love in those who are willing to hear and respond to the divine Word, enabling faith to grow toward reflecting the divine goodness within human limits (Gregory of Nyssa, On the Holy Trin.).

Universal history is therefore a history of the activity of the triune God: (1) Given all by the Father of all, the fall of humanity from its original uprightness is (2) redeemed through God’s justifying activity in the Son, and (3) our faithful response is elicited through the power of the Spirit. To say that creation as given is good, that the fall of freedom is uprighted by justification and consummated by sanctification, is therefore another way of saying that God meets us in history as Father, Son, and Spirit (Hilary, Trin. 7). This triune history of salvation brings together all the basic issues of Christian theology in a single wide angle frame: creation, redemption, and consummation.

This orthodox view of universal history is intimately interwoven with the triune understanding of God: God the Father is giver and ground of all things; God the Son is God Himself entering into this sphere to declare the primordial love of God and make known God’s Word to us; God the Spirit empowers the fulfillment of the divine purpose in redemption (Gregory of Nyssa, On the Baptism of Christ).

We now exist in an ongoing historical process in which, through the gifts of the Spirit, this love is appropriated through church, sacraments, and ministry in the hope of sanctification, through which God perfects what God has created and redeemed. The Holy Spirit has been eternally present throughout the whole historical process, but is now powerfully present in the mission of enabling faith in the Son and guiding the church “into all truth” (John 16:13; Augustine, Tractates on John 96–100; Chrysostom, Hom. on John 79).

Faith’s Experience of Trinitarian Reasoning

Deciding About Jesus

This summary way of thinking began very early, even while the New Testament was being written, when people began to try to make up their minds about what was happening in their encounter with Jesus of Nazareth. They recognized that in Jesus they had come to know God the Father through his Son. Jesus himself often spoke of God as Father (patr, Mark 11:10, 25 f.; 13:32; 14:36; Matt. 6:1–32; 10:20–37; 18:10–35; 26:39–42) or familiarly as Abba (“papa,” Mark 14:36). The intimate and affectionate name, Abba, echoes throughout the Pauline letters (Rom. 8:14; Gal. 4:6). At Pentecost, the disciples received the promise of the Father (Acts 1:4; 2:32).

It was not merely that Jesus was teaching about God, the Father. Rather, the church believed that God the Father was intimately and personally present in Jesus’ ministry, and that Jesus himself was personally present in the life of the community as resurrected Lord. They felt the real presence of the Father with them. The Son’s presence was experienced as nothing less than the Father’s own living, personal presence.

The Johannine writings spoke in a voice that would affect all triune teaching: “God’s only Son, he who is nearest to the Father’s heart, has made him known” (John 1:18; Irenaeus, Ag. Her. 4.22.7; Hilary, On the Councils 36). “We know also that the Son of God has come and has given us understanding, so that we may know him who is true. And we are in him who is true—even in his Son Jesus Christ. He is the true God and eternal life” (1 John 5:20). Christ not only makes God known, but is truly God; not only reveals the truth, but is the truth; and the worshiping community understands its life to be hid “in Christ.” It is this Word of God who was “with God in the beginning” and who “was God,” who “came from the Father,” who had “become flesh and lived for a while among us” (John 1:1–14; Irenaeus, Ag. Her. 3.11; Ambrose, On the Incarnation 6.59). In these passages, we are listening in on the earliest Christian community seeking to speak accurately of its actual experience of the real presence of God in Jesus.

This implied no disregard for the oneness of God. The earliest Christians were steeped in monotheistic faith, but they had to make sense out of this decisive event—this living presence of the risen Lord in their midst. They understood Jesus to be not part God, not merely similar to God, but in the fullest sense “true God” (John 17:3; 1 John 5:20; Rev. 3:7; Irenaeus, Ag. Her. 3.9; Chrysostom, Hom. on John 80.2). This is the reason we have triune thinking. If the first generation witnesses had not been bathed in that vital experience, we would not be talking about the Trinity today. In that sense, the core of triune teaching did not undergo a century of development before being realized, but was grasped in the first generation of witnesses.

The disciples not only experienced the presence of Father and Son but further experienced a powerful impetus of the divine Spirit that brought the Son into their hearts. They understood that this Spirit was working within their community to awaken and teach them the significance of what happened in Christ—counseling them, helping them to understand, praying with them, accompanying them. This gave them unusual courage and hope. The Holy Spirit was that living and present reality in the life of the community, distinguishable from, but not separable from, the same one God who was self-disclosed and present in Jesus (Irenaeus, Ag. Her. 3.17; Tertullian, Ag. Praxeas 1–15; Tatian, To the Greeks 15).

Gradually, as the Christian community moved from Jerusalem into the Greek, Syriac, and Latin environments, they struggled to articulate this experience in varied language and symbol systems. Christians today continue to be encountered by the same loving Father, risen Lord, and empowering Spirit. Christians today are relearning how to address God as Father of our Lord Jesus Christ through the guidance of the Spirit. Christians today still live out of the same remembered history of the saving deeds of God as Father, Son, and Spirit.

Unity, Equality, and Distinguishability

The nucleus of triune teaching is to learn how to affirm simultaneously three aspects: the equality and unity and distinguishability of Father, Son, and Spirit in our encounter with the one God. Physical objects have three dimensions—length, breadth, and height. They are distinguishable, but inseparable, unified in a single object, yet three-dimensional. Our experience of the physical world always has three aspects—space, time, and matter. These are unified in the being of any physical object, yet clearly distinguishable. The seeming paradox of three in one is familiar to the human experience of physical reality (Augustine, Trin. 8.10; Tho. Aq., ST 1 Q12, 13).

God has left soulprints of triunity everywhere in the created order. There are in perception (a) external objects encountering (b) the mind that is capable of (c) perceiving external objects. Thus in a common human function such as perception, there is a threefold unity as an act of perception which requires the mind, objects, and the act of perceiving (Augustine, Trin. 9.1–12). The unity of selfhood is made up of memory, understanding, and willing, showing how a personal subject-self may remain one while being threefold as memory, understanding, and will: “Whatever else can be predicated of each singly in itself, is predicated of them all together in the singular and not in the plural” (Augustine, Trin. 10.17–19). Love requires a lover, a beloved, and a love that unites them, in a kind of three-in-oneness, for in speaking of these three, we are speaking only of a single reality, love (Augustine, Trin. 8.4–10, 9.9–12). All these three-fold patterns display unity, equality, and distinguishability (Tho. Aq., ST 1 Q42), the crucial terms of triune teaching.

Tri-unity—Three-in-one-ness

The English word trinity from the Latin trinitas (tres, three, unus, one) signifies that God is three-in-one, or triune, that is, one God—Father, Son, and Holy Spirit—a teaching distinctive to Christianity. It is hardly found in philosophical theisms, and only occasionally in the history of non-Christian religions. Its key assumptions are indirectly anticipated, but not expressly taught, in prophetic Scriptures of the Old Testament.

Some will resist the notion of trinity because it is thought to be not found expressly in Scripture, but we will show that the Scriptures require the teaching of one God as Father, Son, and Spirit. These interrelated texts are found throughout the Bible, and especially in crucial summative points of biblical teaching (Augustine, Trin. 1.6; Calvin, Inst. 2.14, 15; Heppe, RD: 105–33). The idea of the triune God is necessary to explain some crucial texts of Scripture.

From the time of the apostolic fathers (Hippolytus, Irenaeus, and Tertullian), triune language has been definitive of orthodox Christian teaching accepted alike by Protestants, Catholics, and Eastern church communions (Council of Nicaea; Gregory Nazianzus, Orat. 38.8). It provides a shorthand term used to express in a single word what Scripture teaches in many discrete passages. It is not merely a speculative or theoretical or optional teaching, but is regarded by consensus as essential to the Christian understanding of God (Gregory Thaumaturgus, COC 2: 24; Athanasian Creed; Augsburg Conf. I; Thirty-nine Articles). Baptism has never been administered in the name of one God and two creatures. That would have been the outcome of Arianism, so it had to be rejected as unscriptural (Athanasius, Four Discourses Ag. Arians 2.41; Gregory Nazianzus, On the Great Athanasius 13). Scripture insists that the Son and Holy Spirit are not creatures but truly God. (Hilary, Trin. 1.6). Scripture constrains Christian teaching to speak of Jesus as God’s own Son, not a creature, and not less than God; and the Holy Spirit as God’s own Spirit, not less than God, and not a creature (Calvin, Inst. 2.14.3–8).

The triune teaching may seem to assert a contradiction: that God is three, and that God is one. One early incomplete teaching (modalism) attempted to “resolve” this contradiction by stating that God has three distinct modes that are not simultaneous: only one of these modes is manifested at any given time. The early church vigorously opposed this premature solution on the grounds that it did not make sufficiently clear that in Scripture God does not cease being the Father when God is the Son (Dionysius, Ag. the Sabellians).

The obedience of the Son to the Father (John 15:10) does not imply that the Son is inferior to the Father. The Son did not become less than the Father by becoming eternally obedient to the Father’s will (Phil. 2:5–11; Marius Victorinus, Ag. Arians 1.21–23). The Spirit serves the mission of the Son on behalf of the Father: “When he comes who is the Spirit of truth, he will guide you into all the truth; for he will not speak on his own authority, but will tell you only what he hears; and he will make known to you the things that are coming. He will glorify me” (John 16:13, 14; Didymus the Blind, On Holy Spirit 34–37).

If God is one indivisible unity, any distinction referred to must not divide God into two, three, or more separable parts. “God is one,” proclaimed the New Testament, echoing ten centuries of Hebraic monotheism (1 Tim. 3:20). “For there is one God, and also one mediator between God and men, Christ Jesus, himself man, who sacrificed himself to win freedom for all mankind” (1 Tim. 2:5, 6; Gregory of Nazianzus, Theol. Orat. 4.30.14). Jesus himself clearly affirmed the Hebraic teaching of the unity of God when asked which is the first commandment: “Hear, O Israel: the Lord our God is the only Lord” (Mark 12:29). Unity is implied in the very idea of God, properly conceived (Tho. Aq., ST 1 Q39). There cannot be more than one necessary being (John of Damascus, OF 1.5). For Christian teaching does not say that they are three in the same sense that they are one, which might cause us to say foolishly, “He are one” or “they is three.” God is one. Father, Son, and Spirit are three. God’s unity is not a unity of separable parts but of distinguishable persons.

Scriptural Roots of Trinitarian Reasoning

Classic Consensus on the Cohesion of Old and New Testament Witness

What follows is an attempt to set forth major consensual views of the most influential classical exegetes like Athanasius, Hilary of Poitiers, Augustine, and Cyril of Alexandria, on how the one God revealed to Israel is none other than the same triune God revealed in Jesus Christ.

Their thesis: The triune teaching has become incrementally clarified as established teaching by passing through successive stages: preindications in the Old Testament; the central disclosure of God as Father, Son, and Spirit in the New Testament; and the full development of church teaching in the Nicene definition and its subsequent interpretations.

Classic Christian interpreters agree: The first generation of witnesses have pointed to the fulfillment of the Old Testament prophesies. They could not read about the promise of God to Abraham, Moses, and Isaiah and the Psalms without noticing that these promises had been fulfilled in Jesus Christ (Athanasius, Ag. Arians; Aphraates, Demonstrations).

The Spirit of God is often mentioned throughout the Old Testament (Exod. 31:3; 35:31; 1 Sam. 16:13–23; Ps. 51:10, 11; Isa. 11:2; Gregory Nazianzus, On Pentecost 9). The Spirit of God is giver of life: “For the spirit of God made me, and the breath of the Almighty gave me life” (Job 33:4; Ps. 33:6). The same Spirit inspired Moses and the prophets: “Then the Lord came down in the cloud and spoke with him, and he took of the Spirit that was on him and put the Spirit on the seventy elders. When the Spirit rested on them, they prophesied” (Num. 11:24, 25; Cyril of Jerusalem, Catech. Lect. 16.25).

The Spirit is omnipresent: “Where can I go from your Spirit? Where can I flee from your presence?” (Ps. 139:7). Isaiah 48:16 is a principal prophetic text from which classical exegetes have argued a decisive triune intimation. The speaker is the Lord’s Servant, the promised Messiah: “‘Come near to me and listen to this: From the first announcement I have not spoken in secret; from the time it happens I am there.’ And now the sovereign Lord has sent me, with his Spirit” (Isa. 48:16, italics added; Jerome, Comm. on Is. 13.16). The first person me has been widely thought by classical exegetes to be anticipatory of the Son, viewed as a fulfillment of prophetic promise. Already Isaiah is found speaking discretely of the Lord God by whom the Servant Messiah is sent and the Spirit with whom he is sent, thus keeping all the primary elements of triunity in place: unity, distinction, and complementary mission (Origen, Ag. Celsus 1.46; Augustine, Trin.2.5; Tho. Aq., ST 1 Q31).

In the first two verses of the Bible, God and the Spirit of God appear in conjunction; for it is said that “God created,” and “the Spirit of God was moving over the face of the waters” (Gen. 1:1, 2; Hilary, Trin. 2.13–16). Where the text says: “In the beginning of creation, when God (Elōhīm) made heaven and earth,” Elōhīm is a plural noun, yet linked with a singular verb. God and God’s Spirit appear distinguishable, yet God is one (Ambrose, Of the Holy Spirit 2.1). When “God said, ‘Let us make man in our image and likeness’” (Gen. 1:26), a startling implication emerges: The one God is speaking in the first person in plural form. Common in prophetic teaching are phrases such as: “I am with you, says the Lord of hosts, and my spirit is present among you” (Hag. 2:1–5, italics added; Cyril of Jerusalem, Catech. Lect. 16.25–28).

The occurrence in prophetic literature of a threefold repetition of the divine name has been viewed by classical exegetes as a precursor of triune teaching: “Holy, holy, holy [the threefold name of the One God] is the Lord of Hosts: the whole earth is full of his glory’” (Isa. 6:2, 3; Origen, OFP 1.3; Ambrose, Of the Holy Spirit 3.16, 109–11). This threefold repetition of the divine name recurs again in the Revelation of John: “Holy, holy, holy is God the sovereign Lord of all, who was, and is, and is to come!” (Rev. 4:8, italics added; Athanasius, On Luke 10:22, sec. 6). When the one Lord appeared to Abraham by the oaks of Mamre, he was manifested in the appearance of “three men” (Gen. 18:2)—Abraham “saw three and worshipped One,” commented Ambrose (Holy Spirit 2.Intro.4).

No single text of Scripture has been viewed as standing alone, yet many references to Fatherhood, Sonship, Word, Wisdom, and Spirit have been viewed in correlation with each other as triune allusions, as borne out in the history of triune exegesis. This exegesis has proceeded under the principle of the analogy of faith, by which one passage of Scripture is examined and understood in relation to what is known of other passages (Calvin, Inst. 1.6–9, 1.13.3; Baxter, PW 12:141–47). In this way the truth of Scripture is revealed not as separable parts, but as a whole, to be grasped integrally and intuitively by the discerning reader as a single, reliable revelation of truth.

The plural forms of speech for God are linguistic intensives, emphasizing the fullness of the divine majesty, the glory of the Lord of hosts. The plural is at times preferred even when the intent is to assert the unity of God, as in the Sh-ema’: “Hear, O Israel, the Lord is our God” (literally, “our Gods,” Elōhēnū), “one Lord” (Deut. 6:4). “Remember your Creator in the days of your youth” (Eccles. 12:1) is literally “Remember your Creators” (Eth-Bōrekā). Even if these linguistic intensives do not carry the strength of a full argument, they have been viewed as a corroboratory point for the devout reading of Scripture that has become subsequently informed by fuller triune teaching (Athanasius, Four Discourses Ag. Arians 2.23; Hilary, Trin. 7.10, 12.37). At least one New Testament writer argued that Old Testament inspiration was implicitly trinitarian in intent:

This salvation was the theme which the prophets pondered and explored, those who prophesied about the grace of God awaiting you. They tried to find out what was the time and what the circumstances, to which the spirit of Christ in them pointed, foretelling the sufferings in store for Christ and the splendors to follow; and it was disclosed to them that the matter they treated of was not for their time but for yours. And now it has been openly announced to you through preachers who brought you the Gospel in the power of the Holy Spirit sent from heaven. These are things that angels long to see into. (1 Pet. 1:10–12)

The Old Testament does not provide Christian teaching with a full disclosure of the triune teaching, but it does contain important preindications of it. This is what we might reasonably expect if we affirm consistently that God’s will is revealed through his Word speaking through history, so that subsequent historical events are illumined by and illuminate God’s self-presentation in prior events. Scripture does not treat the triune teaching as an abstract proposition of speculation, but rather reveals the unity of the diversely active God in creation, providence, redemption, and consummation.

The New Testament Unfolding of the Triune Teaching

Triune teaching is not just a belated Hellenistic invention of the post-Nicene fathers, as some modern commentators have claimed. Rather, it is from the New Testament that ancient ecumenical teaching directly derived its primary conclusions that the Father is God, that the Son is God, that the Spirit is God, and that God is One.

The surest way to establish that the Father is God, the Son is God, and the Spirit is God is by a classical fourfold exegetical exercise that shows textually how in Scripture (a) each Person (Father, Son, Spirit) is distinguishably addressed by divine names; (b) each is assumed to have divine attributes; (c) each engages in actions that only God can accomplish; and (d) each is thought worthy of divine worship (Cyril of Jerusalem, Catech. Lect. 7; Tho. Aq., ST 1 Q33; Quenstedt, TDP 1: 329; Watson, TI 1: 475; and Bavinck, DG 4).

The Father Is God in the New Testament

The first conclusion drawn by ecumenical exegetes is that God is called Father in Scripture. The primary textual evidence for this conclusion is as follows:

Jesus characteristically called God his “Father” (Matt. 5:45; 6:6–15; Mark 14:36). He insistently taught his disciples to call God by the name “Father.” This is clear in Jesus’ response to Mary: “I am now ascending to my Father and your Father, my God and your God” (John 20:17; Gregory of Nyssa, Ag. Eunomius 2.8). It is this Father who sends “his only Son, that everyone who has faith in him may not die but have eternal life” (John 3:16). It was precisely his persistence in speaking of God affectionately as “his own Father” that caused his detractors to become “still more determined to kill” Jesus, “because he was not only breaking the Sabbath, but by calling God his own Father, he claimed equality with God” (John 5:18, italics added;. Novatian, Trin. 21–27). Claiming equality with God was the worst offense against Jewish sensibilities to be made by Jesus. From these texts the classical exegetes had no hesitation in concluding that the Father is God (Cyril of Jerusalem, Catech. Lect. XI; Hilary, Trin. 9.61).
To the Father attributes are ascribed that could only belong to God. Among them are holiness, “Holy Father” (John 17:11); sovereignty, “Father, Lord of heaven and earth” (Matt. 11:23); eternity, “Eternal God” (Gen. 21:33; Jer. 10:10); all-powerfulness, “Abba, Father,’ he said, ‘all things are possible to thee’” (Mark 14:34). One who is holy, almighty, and eternal must be nothing less than God (Cyril of Jerusalem, Catech. Lect. 7.1 ff; Hilary, Trin. 11.16; Tho. Aq., ST 1 Q33).
To the Father are ascribed works done by God alone as creator, redeemer, and consummator: “For us there is one God, the Father, from whom all being comes, towards whom we move” (1 Cor. 8:6). “Praise be to the God and Father of our Lord Jesus Christ, who in his great mercy gave us new birth into a living hope by the resurrection” (1 Pet. 1:3). The Father sends the Son (John 5:37; Hilary, Trin. 9.20). One who does the works of God must be none other than God (Athanasius, Four Discourses Ag. Arians 3.25).
On these scriptural grounds it is only appropriate that God should be worshiped as Father: “The time approaches, indeed it is already here, when those who are real worshippers will worship the Father in spirit and in truth. Such are the worshippers whom the Father wants” (John 4:23; Origen, Comm. on John 13.86–100). “If you ask the Father for anything in my name, he will give it to you” (John 16:23). One to whom worship is due must be worthy of the name God (Novatian, Trin. 7; Hilary, Trin. 6.30).

The Son Is God in the New Testament

“O God, thy God has set thee above thy fellows, by anointing with the oil of exultation” (Heb. 1:9). The unique phrase “O God, thy God” makes no sense without a triune premise (John of Damascus, OF 4.6). This Son is explicitly described as equal to God the Father (John 15:17; Gregory Nazianzus, Orat. 38.8; Ambrose, Of the Chr. Faith 3.3). He is “only Son” of the Father (John 1:14), “God’s only Son” who is “nearest to the Father’s heart” (John 1:18).

The frequency and intensity of these ascriptions of lordship and unique divine sonship to Jesus Christ make this one of the most distinctive and unavoidable themes of the New Testament (Gregory Nazianzus, Fourth Theol. Orat., On the Son 20). Those who try to interpret the New Testament without the triune premise have great difficulty making sense of many New Testament texts. Paul speaks also of Jesus as God’s “own Son” (Rom. 8:32), whose name is “above every name” (Phil. 2:9; Athanasius, Defence of the Nicene Definition 3; Tho. Aq., SCG 4.11).

Second, Christ is celebrated in Scripture as having attributes that could be intrinsic qualities of God alone: eternal (Matt. 28:20; Heb. 1:8; 13:8; John 1:1, 14; 1 John 1:2); uncreated, underived, for the Son “has life-giving power in himself” (John 5:26), who “exists before everything” (Col. 1:17; Calvin, Inst. 1.13.8). Only God can be uncreated (Athanasius, Four Discourses Ag. Arians 1.4). He is all-knowing: “He knew men so well, all of them, that he needed no evidence from others about a man, for he himself could tell what was in a man” (John 2:25). Peter said to Christ: Lord, “you know everything” (John 21:17). The Son is remembered as foreknowing, “I saw you under the fig-tree before Philip spoke to you” (John 1:48); as “the same yesterday, today, and for ever” (Heb. 13:8); the “power of God and the wisdom of God” (1 Cor. 1:24); who will “put everything in subjection beneath his feet” (Eph. 1:22); who will transfigure our bodies “by the very power which enables him to make all things subject to himself” (Phil. 3:21). “Full authority in heaven and on earth has been committed to me” (Matt. 28:18). Only God has such power. Thus the classical exegetes concluded that, if Christ has God’s attributes, then Christ is God, and the Son has been properly named as the Son of God (Athanasius, De Synodis, Councils of Ariminum and Seleucia 3.49–52; Cyril of Jerusalem, Catech. Lect. XI; Confession of Wittenberg 2).

Third, the Son of God, does works that are peculiar to God, and thus must be God. For who but God could create (John 1:3; Col. 1:16; Heb. 1:10); preserve and govern all things in being (John 5:17; 1 Cor. 8:6; Col. 1:17; Heb. 1:3); or oversee the expected consummation? (2 Cor. 1:2; John 5:22). Who but God can forgive sins? (Mark 2:7). Who but God can raise the dead? (John 6:39–40; 11:25; Apostolic Constitutions 5.1.7). Jesus did all these things (Gregory Nazianzus, Orat. 3, On the Son). It was the New Testament eye-witnesses first—and only therefore the later ecumenical teachers—that described Jesus as greater than Moses, greater than David, greater than Solomon, greater than John or the prophets, greater than the superpersonal intelligences that inhabit the higher regions (Matt. 3:11; 12:41 f.; Mark 12:37; Luke 11:31, 32; John 1:17; Eph. 1:21; Heb. 1:4 f.; Cyril of Jerusalem, Catech. Lect. 12.15). Hence the Son is God.

Fourth, only God is worthy of worship, for that is what it means to be God. If the Son is called God, if the Son is like God in every personal attribute or quality intrinsic to God, and if the Son of God does what God does, then the Son is worthy of worship as the only true God. This is why “the men in the boat fell at his feet, exclaiming, “Truly you are the Son of God’” (Matt. 14:33). “To deny honor to the Son is to deny it to the Father who sent him” (John 5:23; Hilary, Trin. 9.23).

Father and Son remain clearly distinguishable—one is said to send, the other to be sent. One gives, the other is given. One bestows power, the other receives it (John 12:44–49; 17:18–25; John of Damascus, OF 3.45). Thus we cannot come away from these New Testament texts saying that God is at one time Father and at another time Son (as modalism asserts), but eternally both—distinguishable, yet equal (Hilary, Trin. 4,5). It is the New Testament itself and not just subsequent dogmatics that insists upon a distinction between equal persons in the triune God. A personal relation eternally exists between Father and Son. This is why the New Testament teaching of God is so irrevocably triune.

The Spirit Is God in the New Testament

The Holy Spirit is a speaking, encountering, interacting Person distinguishable from the Father and Son. The Spirit speaks in the first person as “I”: “It was I who sent them” (Acts 10:20). It was the Holy Spirit who said, “I have called them” (Acts 13:2; Chrysostom, Hom. on Acts, 27). None but a person can say “I.” The Holy Spirit does what only personal agents can do: the Spirit grieves (Eph. 4:3), struggles with other persons (Gen. 6:3; Isa. 63:10), provides leadership (Rom. 8:14), witnesses (1 Cor. 1:22; 5:5; Eph. 1:13, 14), and bestows gifts (Eph. 6).

Scripture views the Spirit as nothing less than God because the names ascribed to the Spirit are names that could only be ascribed to God: “the Spirit of God,” “Spirit of the Lord,” “the Holy Spirit of promise,” “the Spirit of wisdom,” “the Spirit of truth,” and the Counselor or Comforter (Acts 1:8; John 4:24; 14:21; 15:26; Rom. 8:14; Cyril of Jerusalem, Catech. Lect. 16; Tho. Aq., ST 1 Q36). Scriptures report God as addressing hearers through “My Spirit” (Gen. 6:3; Prov. 1:23; Isa. 44:3; Ezek. 36:27; 39:29; Joel 2:28; Matt. 12:18; Acts 2:17, 18).

The Spirit is divine Counselor (Advocate, Comforter, Paraclete) whose counsel is incomparably wise (John 14:16; 15:26; 16:7). “The Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and bring to your remembrance all that I have said to you” (John 14:26; Augustine, Tractates on John 77.2). “When the Spirit of truth comes, he will guide you into all the truth” (John 16:7–13; Hilary, Trin. 8.19; Calvin, Inst. 1.13.15). Only God could guide the believer to all truth.

Scriptures view the Spirit as God because the attributes of the Spirit are God’s own attributes. The Spirit is eternal (Heb. 9:14), omniscient (1 Cor. 2:10–12), and all-powerful (Luke 11:20; Rom. 15:18, 19). Only the Spirit of God is able to “explore everything, even the depths of God’s own nature” (1 Cor. 2:10; Cyril of Jerusalem, Catech. Lect. 16.1–11; Gregory Nazianzus, Fifth Theol. Or; Ambrose, Of the Holy Spirit 1.5).

The works done by the Spirit are God’s own work. It is through the Spirit that “God has revealed to us” “things beyond our imagining” (1 Cor. 2:9–10; Clement of Alex., Strom. 2.7.3). It is this same Spirit of God who bears witness to the truth in Jesus Christ (Acts 5:30–32); who gives new life to believers (Titus 3:5); strengthens the faithful (1 Cor. 6:19); and gives the gifts of ministry (1 Cor. 12; Eph. 6). Only God can remit sin (John 3:5), give life (John 6:63), sanctify sinners (2 Thess. 2:13; 1 Pet. 1:2), perform miracles (Matt. 12:28; Luke 1:35), and bring life out of death (Rom. 8:11; Augustine, Trin. 5.8–16; Calvin, Inst. 1.13.14; Wesley, On the Holy Spirit, WJW 7:508).

The Spirit is God because the worship due the Spirit is a worship due to God alone (Gregory Nazianzus, Orat. 5.1–12; Basil, On the Holy Spirit 18; John of Damascus, OF 1.7). For “God is spirit, and those who worship him must worship in spirit and in truth” (John 4:24; Basil, On the Holy Spirit 26.64). Wherever persons are baptized, they are baptized in the name not only of the Father and the Son but also of the Spirit, one God (Matt. 28:19).

If these four persistent exegetical arguments are rightly conceived, it would be absurd to argue that the triune teaching is not found in the New Testament.

Trinity as Summary Digest of New Testament Teaching

There can be no triune teaching without Scripture, and there can be no adequate explanation of Scripture without the triune teaching. The Scriptures so conspicuously affirm the deity and unity of Father, Son, and Spirit that we must conclude that the Nicene fathers were right to develop the triune teaching in the way they did in their historical context. Nicaea was not an extra-biblical addition.

Here are a few core passages of Scripture in which Father, Son, and Spirit are coordinately presented—locus classicus texts that reveal the triune teaching in its summative sense. Only twelve are cited, but many more could be added. If we had nothing but these passages, it could be reliably established that the triune teaching was already powerfully present in New Testament teaching.

The Baptismal Formula. The apostles were commissioned by Christ to “Go forth therefore and make all nations my disciples; baptize men everywhere in the name of the Father and the Son and the Holy Spirit” (Matt. 28:19; for classical exegesis, see Hilary, Trin. 2.15; Basil, Letters 159.2; Chrysostom, Gospel of Matthew hom. 90.2). If there is no distinction between Father, Son, and Spirit, why the necessity of the three distinct names? If there is no equality of these persons, why are they linked together at such a crucial teaching moment in the early church? Christian baptism is administered “in the name of” not three Gods, not two creatures plus one God, not three parts of God, and not three stages of God, but one God who is eternally Father, Son, and Spirit (Gregory of Nyssa, On “Not Three Gods”). The history of Christian theology is best understood as an extended commentary on the baptismal formula (Gregory Nazianzus, Ag. Eunomius 2.1, 2; Ambrose, On Sacr. 1.18, 2.14–24). Its liturgical importance, its strategic location in the received canonical Gospel of Matthew as the final command of the Lord, and the fact that it has been so frequently referred to by early Christian writers make this text the centerpiece of triune teaching. It affirms the divinity, the distinctness, the equality, and the unity of the Father, Son, and Spirit. It calls for an act of adoration and profession of faith in the triune God (Cyril of Jerusalem, Catech. Lect. 16.4).

Jesus’ Baptism. The Father, with the Spirit, blesses the Son at Jesus’ baptism, according to Matthew’s Gospel. When Jesus was baptized, the Holy Spirit descended upon the Son, and the Father spoke from above: “After baptism Jesus came up out of the water at once, and at that moment heaven opened; he saw the Spirit of God descending like a dove to alight upon him; and a voice from heaven was heard saying, ‘This is my Son, my Beloved, on whom my favor rests’” (Matt. 3:16, 17, see also Mark 1:10–11; Luke 3:22; Augustine, Sermon 2.1–2). In this passage, Father, Son, and Spirit are all present in an explicit triune inauguration of the messianic ministry (Didache 7:3; Irenaeus, Ag. Her. 3.9; John of Damascus, OF 3).

Paul’s Apostolic Benediction. The Pauline tradition carries many indications that the triune formula was available in oral tradition prior to Paul’s writing. Notably, Paul closed his second letter to Corinth with a threefold benediction that joined together equally and distinctly the Spirit with God and Christ: “The grace of the Lord Jesus Christ, and the love of God, and the fellowship in the Holy Spirit, be with you all” (2 Cor. 13:13). This is a solemn benediction offered up in supplication to God at a critical moment of the Epistle—its conclusion. Chrysostom shows how “all that belongs to the Trinity” is benediction (Hom on Cor. 30.3): The love of God the Father which has been manifested through grace in Jesus through the power of the Holy Spirit that is blessing the church at Corinth (Gregory of Nyssa, Ag. Eunomius 1.16; Ambrose, Of the Holy Spirit 1.12.131). Paul wrote to the Corinthians: “No one can say ‘Jesus is Lord!’ except under the influence of the Holy Spirit. There are varieties of gifts, but the same spirit. There are varieties of service, but the same Lord. There are many forms of work, but all of them, in all men, are the work of the same God” (1 Cor. 1:4–6). It is the Spirit of God who enables the faithful to believe in the Son of God, “the same God,” whom Jesus calls “Father.”

The Ephesian Formula. The same triune teaching is embedded in the Ephesian formula: “Through him”—Christ Jesus—“we both alike have access to the Father in the one Spirit” (Eph. 2:18). This language suggests that there existed an oral tradition prior to the writing of this letter in which Father, Son, and Spirit, as in the baptismal formula, were frequently linked in familiar order. His prayer was that the God of our Lord Jesus Christ, The Father of glory, may give you a spirit of wisdom (Eph. 1:17; Jerome, To the Ephesians 1.1.15–17). The same letter calls believers to live “in the unity which the Spirit gives,” since “There is one body and one Spirit, as there is also one hope held out in God’s call to you; one Lord, one faith, one baptism, one God and Father of all, who is over all and through all and in all” (Eph. 4:3–6; Chrysostom, Hom. on Eph. 9.4.1–3). The letter to Ephesus teaches the oneness of God who is “Father of all,” of the Lord Jesus Christ, and of the “one Spirit” that unifies the church (Hilary, Trin. 8.13, 11.1; Wesley, WJW 6:392).

Jude’s Summary Call to Prayer. “Continue to pray in the power of the Holy Spirit. Keep yourselves in the love of God, and look forward to the day when our Lord Jesus Christ in his mercy will give eternal life” (Jude 20, 21; Oecumenius, Comm. on Jude 20–21). The call to prayer encompasses the love of God, the hope of Christ, and the power of the Spirit at the climactic moment of the Epistle when the writer is seeking to provide a summative statement of its instruction. Jude’s letter is addressed to those “beloved in God, the Father and kept for Jesus Christ” (Jude 1), to those who were being warned against those “devoid of the Spirit” (Jude 19).

The Johannine Farewell Discourses. Nowhere is the triune teaching stated more distinctly than in John’s report of Jesus’ last discourse to his disciples, in which the Son promises the “Advocate, the Holy Spirit whom the Father will send in my name” (John 14:26: Didymus, On the Holy Spirit 30–31). The Son sends, the Spirit is sent, and the Spirit proceeds from the Father. “When your Advocate has come, whom I will send you from the Father—the Spirit of truth that issues from the Father—he will bear witness to me” (John 15:26; Tertullian, Prescript. Ag. Her. 28; Augustine, Trin. 4.20; John of Damascus, Orth Faith 1.8).

John’s Prologue. The most highly developed teaching of God as Father, Son, and Spirit is in the Fourth Gospel, where all key elements come into explicit expression. The preexistence of the Son is evident: “In the beginning was the Word, and the Word was with God, and the Word was God. He was in the beginning with God. All things came into being through him, and without him not one thing came into being. What has come into being in him was life, and the life was the light of all people” (John 1:1–4; Tertullian, Ag. Praxeas 15; Cyril of Alex., Comm. on John 1.2–3). The Word is God, not less than God, God’s speech to the world, God’s way of letting the divine presence become known to the world. “So the Word became flesh; he came to dwell among us, and we saw his glory, such glory as befits the Father’s only Son, full of grace and truth” (John 1:14; Irenaeus, Ag. Her. 3.10). The Father-Son unity and distinction is richly embedded in the Johannine prologue: The Word (Jesus) is God and is with God. One can be God and be with God only by being God in one sense and being with God in another sense. If Christ is God, then Christ is not less than God. If Christ is with God, then there is a distinction in the Godhead or in God’s own personal being that does not change or limit the unity of God but allows for an intrapersonal dialogue within the eternal being of God (Hilary, Trin. 2.23–35).

The Johannine Letters. The language of John’s letters is even more explicit. No one who reads 1 John: 3–5 can reasonably conclude that there is no trinitarian reference whatever in the New Testament. There we are called to “believe in the name of his Son Jesus Christ,” knowing that “he abides in us, by the Spirit which he has given us.” “By this you know the Spirit of God: every spirit which confesses that Jesus Christ has come in the flesh is of God, and every spirit which does not confess Jesus is not of God” (1 John 3:23–4:3; Theophylact, Comm. on 1 John 3:23). All essential assumptions of triune teaching appear in the passage: Jesus is the Son of God, who abides in us by the Spirit whom the Father has given us, who together constitute the revelation of the One God (1 John 5:4–10, Cyprian, Treatises 1.6; Augustine, Sermons 5.3).

The Salutation in the Revelation of John. The salutation to the churches in the Revelation of John is also a rich mine in which classical exegetes recognized the triune formula embedded: “Grace be to you and peace, from him who is and who was and who is to come,” namely, the one God, Father Almighty, “from the seven spirits before his throne,” that is, the seven gifts of the Holy Spirit, and “from Jesus Christ” (Rev. 1:4–5a; Andrew of Caesarea, Comm. on Apoc. 1.4; Tho. Aq., ST 1 Q39).

Philippians 2. The early Christian hymn in Philippians 2:5–11, usually thought to predate Paul, assumed that Jesus Christ is God, and with God from the beginning. This paradoxical distinction (that Jesus Christ is God and is with God from the beginning) is the invariable premise of trinitarian belief (Athanasius, Four Discourses Ag. Arians 1.11). “The divine nature was his from the first,” who is through the Spirit confessed finally as Lord to the glory of the Father (Marius Victorinus, Epist. To Phil. 2.6–8).

Colossians 1. Here the Pauline tradition speaks integrally of the ways in which God as Father and Son acts to save the world: “He rescued us from the domain of darkness and brought us away into the kingdom of his dear Son, in whom our release is secured and our sins forgiven. He is the image of the invisible God; his is the primacy over all created things. In him everything in heaven and on earth was created” (Col. 1:13–16; Cyril of Jerusalem, Catech. Lect. 12.24; John of Damascus, OF 4.8). Through the Son the Father acts to redeem the world. So let “the word of Christ dwell in you richly,” doing everything in the name of the Lord Jesus, giving thanks to God the Father through him (Col. 3:16,17; Ambrose, Of the Holy Spirit 3.11), expressing unity, equality, and distinction.

Salvation History Summary in Hebrews. The final triune text is the opening passage of the letter to Hebrews: “When in former times God spoke to our forefathers, he spoke in fragmentary and varied fashion through the prophets. But in this the final age he has spoken to us in the Son whom he has made heir to the whole universe, and through whom he created all orders of existence: the Son who is the effulgence of God’s splendor and the stamp of God’s very being, and sustains the universe by his word of power” (Heb. 1:1–4; John of Damascus, Orth. Faith 4.17; Photius, Fragments on Hebr. 1.2–3). Note the triune assumptions of the text: Christ is preexistent, one with God, the stamp of God’s very being, not less than God, higher than the angels and all creaturely powers, yet distinguishable from the Father, whose coming is “attested by the Holy Spirit” (Heb. 3:7; 9:8, 14; 10:15; Athanasius, Four Discourses Ag. Arians 1.13; Origen, OFP 1.2.6).

Although triune teaching was already well formed in the oral tradition that led to the writing of the New Testament, it was not formally developed as dogma without a lengthy process of reflection, spurred by the necessity of addressing heresies. The language of Philippians 2, Colossians 1, the Fourth Gospel, and Hebrews 1 could not remain permanently unexamined. Triune teaching in the New Testament is not speaking of a few isolated texts, but of the fundament of the Gospel of John, the Johannine Epistles, and Revelation, and crucial passages in the Pauline tradition, the pastoral letters, and numerous core texts of the synoptic Gospels. Antitrinitarian views have not been able to show that these recurrent formulations are accidental, or textually spurious, or minor additions, or quirks of a single author. The conclusion: New Testament teaching of God is inevitably and necessarily a triune teaching of God.

Historical Unfolding of Triune Teaching

When Ignatius of Antioch (d. ca. 110) appealed to the Magnesians to “Study, therefore, to be established in the doctrines of the Lord and the apostles,” he prayed that they proceed “in faith and love; in the Son, and in the Father, and in the Spirit,” and that they be subject to the bishop “as Jesus Christ to the Father, according to the flesh, and the apostles to Christ, and to the Father, and to the Spirit” (Ignatius, Magnesians 13; Eph. 9:1; Clement of Rome, Corinth 18). The consensus did not doubt that this sort of triune language was received by Ignatius from the writings of the first generation of eyewitnesses.

The historical unfolding of the scriptural teaching of the triune God was a refinement of teachings explicit in the apostles’ witness and required by consistent reflection upon their texts. The triune teaching is already deeply rooted by the time of Polycarp’s prayer before his martyrdom (ca. 156): “I glorify thee, through the eternal and heavenly High Priest, Jesus Christ, thy beloved Servant, through whom be glory to thee with him and the Holy Spirit both now and unto the ages to come” (The Martyrdom of Polycarp).

By the time Tertullian wrote his detailed reply to Praxeas (AD 213) he was answering intricate questions on the interpretation of the triune God that were under vigorous and sophisticated debate. One must assume that there was at this time an available ecumenical oral tradition of intense familiarity with triune teaching in order for Tertullian to write to his audience in such sophisticated terms as the following: “Thus the connection of the Father in the Son, and of the Son in the Paraclete, produces three coherent Persons, who are yet distinct One from Another. These Three are one essence, not one Person, as it is said, “I and my Father are One’” (Ag. Praxeas 25; On Modesty 21). That Tertullian himself did not invent but rather passed on this language is evident from his own testimony that “this rule of faith has come down to us from the beginning of the gospel, even before any of the heretics, much more before Praxeas” (Ag. Praxeas 2). It would have been impossible for Tertullian to address his audience in this way if there had not been an active and available oral tradition in which such language was understood and under sophisticated debate. Hence the triune teaching was, long before Nicaea, widely received and understood in an explicit and detailed way. It was only on the basis of intricacies of the pre-Nicene discussion that the debate that led to Nicaea may be understood. So those who imagine that triune teaching begins at Nicaea thereby show that they have not paid sufficient attention to the texts mentioned above.

Contemplation of the Triune Mystery

The problem faced by early Christian teaching was not whether Christ was God but how, within the bounds of monotheistic faith, the unity of God could be maintained while holding equally to the deity of One who is distinct from God, the Father.

In order to speak of God the Father revealed in the Son through the power of the Spirit, it is necessary to speak of trinity. But trinity is not merely a concept. One does not first define trinity conceptually and then begin worshiping the triune God. Rather it is the revealed God of Scripture who approaches in a way that elicits and requires triune teaching. Gregory Nazianzus’s poem on the Trinity revealed how central was the triune understanding of God in early Christian worship:

From the day whereon I renounced the things of the world to consecrate my soul to luminous and heavenly contemplation, when the supreme intelligence carried me hence to set me down far from all that pertains to the flesh, to hide me in the secret places of the heavenly tabernacle; from that day my eyes have been blinded by the light of the Trinity, whose brightness surpasses all that the mind can conceive; for from a throne high exalted the Trinity pours upon all, the ineffable radiance common to the Three. (Poemata de seipso I, MTEC: 44)

The contemplation of the triune mystery leads beyond language, logical categories, or concepts proper to human thought, beyond dialectic and beyond dialogue, to the Three in One, into whom the faithful are baptized. Ponder:

No sooner do I conceive of the One than I am illumined by the Splendor of the Three; no sooner do I distinguish Them than I am carried back to the One. When I think of any One of the Three I think of Him as the Whole, and my eyes are filled, and the greater part of what I am thinking of escapes me. I cannot grasp the greatness of That One so as to attribute a greater greatness to the Rest. When I contemplate the Three together, I see but one torch, and cannot divide or measure out the Undivided Light. (Gregory Nazianzus, Orat. 40.41, On Holy Baptism)

Thought races relentlessly between ephemeral dialectical poles when we glimpse the triune mystery. But worship in ancient Christianity did not desire to lay hold of the Trinity in objective language but only to worship God in the way that Scripture enables and attests. God is neither one nor three without being three in one.

God transcends alleged monotheistic unity that remains unrevealed in history. God transcends Hellenistic polytheistic multiplicity. God transcends dualism that divides. Two is the number that divides; three is the number that transcends division (Gregory Nazianzus, Orat. 23.10). When Basil’s critics complained that Christianity was submitting God to an external criterion, namely, the idea of number, Basil replied: “For we do not count by way of addition, gradually making increase from unity to multitude, and saying one, two, and three,—nor yet first, second, and third. For ‘I,’ God, ‘am the first, and I am the last.’ And up to this point we have never, even at the present time, heard of a second God. Worshipping as we do God of God, we both confess the distinction of the persons, and at the same time abide by the One” (Basil, On the Spirit 18.45). The number three, when applied to the deity, does not serve as a calculation or quantity but as a unifying referent in the divine unity.

The worshipper enters into the triune mystery only through that ignorance that transcends all concepts, philosophical constructs, and categories. That holy ignorance then returns again to seek language to express itself. Such a language was that of the ecumenical consensus which spoke of the consubstantiality of the Three, the unity of the one nature, and the distinction of the three persons (hypostases). They availed themselves of the terms ousia (substance) and hypostasis (persona, or person) to bespeak the mystery of three in one.

When I speak of God you must be illumined at once by one flash of light and by three. Three in Individualities or Hypostases, if any prefer so to call them, or persons, for we will not quarrel about names so long as the syllables amount to the same meaning; but One in respect of the Substance—that is, the Godhead. For they are divided without division, if I may so say; and they are united in division. For the Godhead is one in three, and the three are one, in whom the Godhead is, or to speak more accurately, Who are the Godhead. Excesses and defects we will omit, neither making the Unity a confusion, nor the division a separation (Gregory Nazianzus, Orat. 39.11, On the Holy Lights)

Father, Son, and Spirit are one in every way except that of being unbegotten (with respect to the Father), of filiation (with respect to the Son), and of procession (with respect to the Spirit).

For the Father is without cause and unborn; for He is derived from nothing, but derives from Himself His being, nor does He derive a single quality from another. Rather He is Himself the beginning and cause of the existence of all things in a definite and natural manner. But the Son is derived from the Father after the manner of generation, and the Holy Spirit likewise is derived from the Father, yet not after the manner of generation, but after that of procession. And we have learned that there is a difference between generation and procession, but the nature of that difference we in no way understand. (John of Damascus, OF 1.8)

If asked further to define the modes of generation and procession, Gregory the Theologian answered: “What is the procession of the Holy Spirit? Do you tell me first what is the Unbegottenness of the Father, and I will explain to you the physiology of the generation of the Son, and the procession of the Spirit, and we shall both of us be frenzy-stricken for prying into the mystery of God” (Gregory Nazianzus, Orat. 31.8, On the Holy Spirit). It is sufficient to distinguish that the Son is begotten and the Spirit proceeds from the Father, following John’s Gospel, and leave speculation to the foolish, imprudent, careless and unwise.

The Triune Structure of Christian Teaching

The incarnation requires triune teaching. The Father freely determines to make himself known. The incarnate Son makes the Father known. The Spirit enables the meaning of this disclosure to be received. If there were only Father and Son, and no Spirit, there would be no consequences of the revelatory event. The Word of God to humanity would lack divine follow-up and remain a past event without effect. Suppose Jesus came and nothing else happened. Then there would be only two persons in the divine mission, and we would have a binity, not a trinity. But Jesus’ mission was in fact followed by an empowering of the Spirit, acting to fulfill and consummate this mission (Ambrose, Of the Holy Spirit 1.7–16). This was not just an odd erratic order into which Christian teaching accidentally fell. Rather, this triune teaching belongs intrinsically to God’s personal self-disclosure, which intends to be heard and appropriated in human history.

It is not some historical fluke that the Apostles’ Creed has three articles, and hence a triune structure: God the Father Almighty, God revealed in the Son, and God the Spirit currently present in the church manifesting the power of the resurrection (Interrogatory Creed of Hippolytus, CC: 23). Early Christian theology developed in order to explain concisely to the believer the meaning of his or her baptism. From the beginning the apostolic tradition has been baptizing in the name of the Father, the Son, and the Holy Spirit. Christian theology has always been essentially a reasoning toward, from, about, and for baptism, a summary explanation of the meaning of the baptismal celebration of entry into this community.

Note carefully the coherent logic of a traditional diagram (see figure below) found in medieval symbolism. This diagram is taken from W. J. and G. Audsley, Handbook of Christian Symbolism (London: Day and Son, 1865), plate 3.

This “shield of the Holy Trinity” teaches that the Father (P = Pater) is not (non est) the Son (F = Filius), the Son is not the Holy Spirit (SS = Spiritus Sanctus), and the Holy Spirit is not the Father. The Father is distinguishable from the Son, the Son is distinguishable from the Holy Spirit; and the Holy Spirit is distinguishable from the Father. However the Father is God (est Deus), nothing less, and the Son is God, nothing less, and the Holy Spirit is God, nothing less, and God is essentially one (una substantia; Tho. Aq., ST 1 Q31; M. D. Wyatt, Geometrical Mosaics of the Middle Ages).

This picture grasps the essential logic of triune teaching that avoids tri-theism, the errant view that Christians worship three Gods. God’s unity is affirmed in three persons. God is una substantia, one substance, which means that God remains essentially one while becoming known in tres persona, three persons (Augustine, Trin. 7.4–6). The Father is God, the Son is God, the Spirit is God.

To pray to Father, Son, and Spirit is quite different than to philosophize about ideas. That God is willing to experience concretely our human alienations, sorrows, suffering, and death is quite different from philosophical concepts of transcendence and immanence. The philosopher’s ideas may interest us, but faith in the triune God requires response to the One who enters our human sphere of finitude and suffering. Rational morality and natural theology may speak of the human capacity to know and do the good, but Christian proclamation trusts and prays to the eternal One who knows what it means to be betrayed and unjustly condemned, to suffer, to be crucified, and to die.

The worshiping community enters into the life of God’s fully personal presence in the world. The faithful are living in Christ, sharing in his resurrection, praying to the Father through the Son. The Spirit is eliciting and sustaining their understanding of what happened in Jesus’ resurrection (Heb. 1–3; 1 Pet. 1; 1 John 4, 5).