One day in 1677, a young man named Henry Scougal sat down to write a letter of spiritual comfort to a distressed friend. And though Scougal’s life would be tragically cut short a year later at the age of twenty-eight, his letter was copied, passed around, and soon published. You could say it went viral. It’s still in print today.
About half a century later, two brothers by the last name of Wesley were given Scougal’s letter by their mother, Susanna, who had cherished the letter herself. The brothers, in turn, were so taken by it that they shared it with their friend George, who upon reading it, commented, “I never knew what true religion was till God sent me that excellent treatise.” That friend was George Whitefield, who went on to become one of the greatest preachers of the eighteenth century and a catalyst of what would come to be called the Great Awakening. Though he had been in church and a practicing Christian for years, Whitefield traced his own conversion back to reading Scougal’s letter. 1
The letter turns around a question that every age has asked in different ways: What is the heart of true Christianity?
Scougal’s answer was that true Christianity consists not in the trappings of religion, not in going to church or in the saying of prayers, not in the making of orthodox affirmations or any external form. Rather, Scougal wrote, true Christianity consists in a “union of the soul with God, a real participation of the divine nature, the very image of God drawn upon the soul, or, in the apostle’s phrase, it is Christ formed within us … a divine life.” 2
His letter has come to be called, and the title says it all, The Life of God in the Soul of Man.
I remember first reading Scougal’s letter and finding his wording both familiar and shocking. This talk of participation in the divine life was not how I heard the gospel described in any church I had yet visited. In fact, some might consider Scougal’s language to be downright dangerous, even heretical. It may sound more “new age” than “old school.”
But his letter did carry the endorsement of several respected names in the theological tradition of the church. And it was grounded in biblical texts as well. To the questions “What is the good news that Christ brings to this world?” and “What lies at the heart of the gospel?” Scougal’s answer—union with Christ—presented a historical riddle to me.
And the seed of the book you now hold in your hands began with this historical riddle, which provoked me as a young seminary student reading many of the “big names” of church history. Why was it that so many of these writers talked about the gospel in a way most of us don’t hear it today? Why has union with Christ disappeared as a controlling category—or even as a common phrase we use—when we talk about the gospel? Whatever happened to union with Christ? That particular question will be the focus of the next chapter.
But for the remainder of this chapter, we will trace, in an extremely abridged fashion, 3 this theme of union with Christ through some of the seminal voices of what historian Hans Boersma has called “The Great Tradition,” by which he means “the broad consensus of the church fathers and medieval theologians.” 4 We will keep following this thread through the Reformation and up through some surprising voices in the twentieth century.
If union with Christ is truly the “fountainhead of the gospel,” 5 then you would expect to find it emphasized over and over, across the centuries and across theological traditions. And, in fact, that is precisely what you find.
Before we jump in, two caveats are in order. First, to demonstrate that union with Christ has been a dominant theological theme for two millennia would require at least an entire book, and from a master of the tradition—not merely one chapter from me. Perhaps someone else will endeavor to write that book. Here I’ll give just a sampling of representative voices and recommend that if you’d like to learn more, the endnotes to this chapter can direct you to further reading.
Second, I am well aware that these theologians differ on significant points, and I don’t mean to imply, by quoting them next to each other, that all of their views harmonize (even when it comes to what union with Christ means). 6 My goal is to show that one thing they all do agree on is that union with Christ is central and significant.
Three of the most important voices of the early church were Irenaeus (AD 130–200), Athanasius (296–373), and Augustine (354–430).
Irenaeus, a most important defender of Christianity in its earliest days, emphasizes throughout his writings the significance of Christ’s incarnation for our life as his followers:
The Word of God was made man, and he who was the Son of God became the Son of Man, that man, having been taken into the Word, and receiving the adoption, might become the son of God. For by no other means could we have attained to incorruptibility and immortality, unless we had been united to incorruptibility and immortality. 7
The incarnation, Irenaeus says, paved the way and made possible our participation in God’s life, such that now we can be united with the incorruptible, immortal life of God.
In the next century, Athanasius was a heroic voice at the first council of Nicaea in 325, crucial for upholding and defending the full divinity of Christ. And Christ’s full divinity is necessary for our salvation. “For,” Athanasius famously wrote, “[Jesus] became man that we might become divine.” 8
Likewise Augustine, the one name from the early church you probably have heard of, and whose influence is still felt today, speaks of our union with Christ in his seminal work, The Trinity:
For surely if the Son of God by nature became son of man by mercy for the sake of the sons of men (that is the meaning of the Word became flesh and dwelt among us), how much easier it is to believe that the sons of men by nature can become sons of God by grace and dwell in God; for it is in him alone and thanks to him alone that they can be happy, by sharing in his immortality; it was to persuade us of this that the Son of God came to share in our mortality. 9
Historian Donald Fairbairn traces the theme of communion with God through the writings of the church fathers in order to demonstrate why the early church did not struggle as much with what we struggle so mightily with today—integrating theology into our daily lives:
They were able to articulate the connection between the doctrines of the faith and the Christian life in a clearer and more persuasive way than we are usually able to do.… The way the early church avoided the problem of divorcing doctrine from Christian life was by understanding all of Christian life in direct connection to God’s life.… Doctrine, as they understood it, pointed beyond itself to God, in whose life human beings are called to share. 10
For the early church fathers, the incarnation and its continuing importance were central to the idea of salvation because knowing God was not merely a theological exercise but an invitation to commune with God. Theology meant understanding your life as enfolded within God’s own life.
To show that this understanding was innate to the faith of the early believers, and not just theologians, we can read the story of Felicitas, a second-century martyr. Charles Williams (one of the Inklings, a literary discussion group comprised of C. S. Lewis and J. R. R. Tolkien, among others) writes in his book on the history of the Holy Spirit in the church:
Her name was Felicitas; she was a Carthaginian; she lay in prison; there she bore a child. In her pain she screamed. The jailers asked her how, if she shrieked at that, she expected to endure death by the beasts. She said: “Now I suffer what I suffer; then another will be in me who will suffer for me, as I shall suffer for him.” 11
This sense of another in me, says Williams, “in a sentence defined the Faith.” 12 And so from the pens of the theologians to the cries of the martyrs, we can see that union with the indwelling Christ was the sum and substance of the gospel in the early church.
To capture this immeasurable gift of our communion with God, the church fathers used two remarkable Greek words: theosis and perichoresis.
The Greek word theosis is often translated into English as “deification,” and for that reason it is often misunderstood and thus avoided. We fear, particularly in the Western church, any implication that human beings in some sense become gods themselves or get absorbed into God’s life. Yet theosis was the church fathers’ way of talking about what the apostle Peter describes, “He has granted to us his precious and very great promises, so that through them you may become partakers of the divine nature” (2 Pet. 1:4). These theologians were careful to stress that theosis did not mean human beings become divine in the same way that God is divine (eternal, infinite, omnipotent, all knowing, etc.). They staunchly maintained a Creator/creature distinction. Yet they were comfortable, in ways we rarely are today, talking about our participation in God’s own triune life. 13
If you spell out the other Greek word, peri-choresis, you can hear in English what the word conveys: peri (from which we get words such as perimeter) and choresis (from which we get our word choreography)—a dancing circle. The word describes the interrelationship of the persons of the Trinity. That in everything God the Trinity is and does, each of the three persons relates to and engages with each of the other persons. Like an eternal dance, the “choreography” of the Divine Being is singular in its diversity and diverse in its unity. And for the church fathers, one beautiful way of understanding our salvation is our being invited into this dance.
If this sounds foreign to our ears today, Jesus himself promised much the same thing in John: “In that day you will know that I am in my Father, and you in me, and I in you.… If anyone loves me, he will keep my word, and my Father will love him, and we will come to him and make our home with him” (John 14:20, 23).
In emphasizing our participation in God’s life, Irenaeus, Athanasius, and Augustine were simply building off the rich biblical foundation we sketched in the previous chapter. It’s important to remember as we run through these theologians that our confidence is not in their words but in the Scriptures they were faithfully trying to exposit.
For the Middle Ages, we’ll jump in by way of a great work of art from the time period: Dante’s The Divine Comedy. This epic poem about a soul’s journey to the face of God is widely recognized as a masterpiece of world literature. Dante’s pilgrim has three guides along his journey: First, the Roman poet Virgil, who represents classical wisdom and knowledge. Then, Beatrice, the love of Dante’s life. His final guide is someone whom, as I read the poem for the first time, I had never heard of—Bernard of Clairvaux, a twelfth-century monk whose great theme was communion with God through our union with Christ.
Dante’s admiration is the main reason I would choose Bernard of Clairvaux from among the many voices we could choose in the Middle Ages (Anselm, Bonaventure, Thomas Aquinas, etc.). Bernard is a towering figure of medieval theology, and he holds a distinguished place in the history of Christian spirituality as someone of whom all sides (theologically) speak favorably. In the Catholic Church, Bernard is known as “the mellifluous doctor,” a reference to the brilliance of his theological mind and the beauty of his speech. But he was also a seminal influence on the Protestant Reformers, with Luther and Calvin both quoting him extensively and with admiration. 14
If there is a controlling theme in Bernard’s works, it is love, specifically the soul’s journey through the love of God to union with God. So taken was Bernard with this theme that he chose the Song of Songs, the biblical poem celebrating the passionate love of a young married couple, as his lifelong theological project (unfinished) to represent the intimate union between Christ and his bride, the church.
Unfortunately for us, he barely made it through the first chapter of the Song of Songs (on which he wrote eighty-six [!] sermons). But isn’t it remarkable that Bernard thought he could interpret the whole Bible through a love poem celebrating marriage? That for him, Romans and Galatians should be seen through the lens of the Song of Songs? That he saw the intimate love of God and communion with him as the lens for understanding all of the Christian life?
Bernard was clear that our union with Christ is not a marriage of equals but is nevertheless a real spiritual marriage to be experienced in this life, sealed by the kiss of the Holy Spirit. 15 In one of his sermons, Bernard writes:
Oh happy kiss, and wonder of amazing self-humbling which is not a mere meeting of lips, but the union of God with man. The touch of lips signifies the bringing together of souls. But this conjoining of natures unites the human with the divine and makes peace between earth and heaven.… “For he himself is our peace, who made the two one” (Eph. 2:14). 16
Martin Luther (1483–1546) also relied on the New Testament imagery of marriage to affirm the reality of the believer’s union with Christ, stating:
Faith … unites the soul with Christ as a bride is united with her bridegroom. By this mystery, as the Apostle teaches, Christ and the soul become one flesh (Eph. 5:31–32). And if they are one flesh and there is between them a true marriage … it follows that everything they have they hold in common, the good as well as the evil. Accordingly the believing soul can boast of and glory in whatever Christ has as though it were its own, and whatever the soul has Christ claims as his own. 17
Luther is famous for his formula simul iustus et pecator (“simultaneously righteous and sinner”), but while we remember the formula, we may forget that he grounds it here in union with Christ! The mystery of the marriage union between Christ and the soul is what allows sinful people to truly possess Christ’s righteousness and allows Christ to take upon himself our sin, death, and condemnation. 18
Reading the Protestant Reformer John Calvin (1509–1564) firsthand surprised me. While many of his terms were familiar (e.g., justification and atonement), the way he talked about salvation as a whole was quite foreign to me. 19 For instance, Calvin writes, “This is a wonderful plan of justification that, covered by the righteousness of Christ … they should be accounted righteous outside themselves.” 20 This was a familiar idea, but I was unprepared for how he clarifies what he means by “outside themselves”:
Therefore, that joining together of Head and members, that indwelling of Christ in our hearts—in short, that mystical union—are accorded by us the highest degree of importance, so that Christ, having been made ours, makes us sharers with him in the gifts with which he has been endowed. We do not, therefore, contemplate him outside ourselves from afar in order that his righteousness may be imputed to us but because we put on Christ and are engrafted into his body—in short, because He deigns to make us one with him. 21
Here I was, about to become a pastor in that same Reformed tradition, and yet I was amazed to hear one of our theological heroes write about salvation in terms that I had rarely heard from evangelicals, much less Calvinists. I was also not prepared for how much Calvin would write about union with Christ and the Holy Spirit. Here he is again:
We must understand that as long as Christ remains outside of us, and we are separated from him, all that he has suffered and done for the salvation of the human race remains useless and of no value to us. Therefore, to share in what he has received from the Father, he had to become ours and to dwell within us … for, as I have said, all that he possesses is nothing to us until we grow into one body with him … To sum up, the Holy Spirit is the bond by which Christ effectually unites us to himself. 22
For Calvin, union with Christ is not—cannot be—an optional aspect of our salvation. The person of Christ is our salvation. Every benefit of the gospel comes to us through and only through our union with him. For Calvin, the mystery of our spiritual connection to the living, incarnate, crucified, resurrected, and ascended Lord is what it means to be “saved.” 23
Calvin and Luther were both adamant to uphold the idea that righteousness from outside of us is imputed to us (not infused within us) and that we are saved completely by the righteousness of Christ alone, through faith. But in our effort to uphold this most important idea of the Reformation—justification by faith alone—is it fair to ask if we’ve lost hold of what was also important: a robust understanding and enjoyment of our union with Christ? When I read one of Calvin’s most famous historical students, B. B. Warfield (1851–1921), who wrote of Calvin, “above everything else, he deserves, therefore, the great name of the theologian of the Holy Spirit,” 24 I was stunned and left wondering, What? and What happened?
The Puritans of the sixteenth and seventeenth centuries continued the Reformation reliance on union with Christ as central to salvation and the Christian life. Writer J. I. Packer summarizes, “The thought of communion with God takes us to the very heart of Puritan theology and religion.” 25 And scholar Tudor Jones agrees that for the Puritans, union with Christ “is not to be understood as the achievement of a few heroic souls but a divine gift received by all true Christians.” As a movement concerned with earnest personal experience of God, biblical orthodoxy, and simplicity of worship, the Puritan emphasis on union with Christ for individual piety should make sense to us by this point in our historical tour. 26
In a page or two we will hear from John Owen, one of the most famous Puritans. But for now, here’s Puritan preacher Thomas Goodwin: “Being in Christ, and united to him, is the fundamental constitution of a Christian.” 27
After the Puritans, as I’ve suggested earlier in this book, this thread of union with Christ as the central reality of salvation fades into the background and is, for the most part, lost to laypersons. William Evans, in his history of union with Christ, says it loses its central and defining role at this point and becomes relegated to simply an optional aspect of Christian life and experience. 28 Among theologians and academics, the thread continues, albeit faintly.
At the risk of oversimplifying, let’s skip ahead a few centuries to an important voice of nineteenth-century American Protestantism, B. B. Warfield. He is perhaps best known today as a defender of the inspiration and authority of the Bible, but he also wrote and preached on union with Christ. Here, in his sermon “Communion with Christ,” he speaks of it:
The appeal is clearly to the Christian’s union with Christ and its abiding effects. He is a new creation; with a new life in him; and should live in the power of this new and deathless life … The pregnancy of the implication is extreme, but it is all involved in the one fact that if we died with Christ, if we are His and share His death on Calvary, we shall live with Him; live with Him in a redeemed life here, cast in another mould from the old life of the flesh, and live with Him hereafter for ever. This great appeal to their union and communion with Christ lays the basis for all that follows. It puts the reader on the plane … of “in Christ Jesus.” 29
And to show that the significance and centrality of union with Christ has not been completely forgotten, I’ll add three other significant twentieth-century voices. John Murray, longtime professor of systematic theology at Westminster Theological Seminary, concludes:
Nothing is more central or basic than union and communion with Christ. Union with Christ is really the central truth of the whole doctrine of salvation not only in its application but also in its once-for-all accomplishment in the finished work of Christ. 30
Theologian Sinclair Ferguson adds:
The dominant motif and architechtonic principle of the order of salvation should therefore be union with Christ in the Spirit. This lies at the heart of evangelical theology. 31
Lastly, theologian and professor Robert Reymond, in his career-defining work, summarizes the idea:
Union with Christ is the fountainhead from which flows the Christian’s every spiritual blessing—repentance and faith, pardon, justification, adoption, sanctification, perseverance, and glorification. 32
In closing, I thought we’d look at these four names unlikely to be found together. John Owen (1616–1683) is arguably the greatest English theologian; Jonathan Edwards (1703–1758) is arguably the greatest American theologian; Karl Barth (1886–1968) is arguably the most important theologian of the twentieth century; and C. S. Lewis (1898–1963) is inarguably the most popular theological writer of the last hundred years. Regardless if we are aware of it, these four voices have had a decisive influence on Christian history and thought. So rather than treat them in their respective historical periods, I thought I’d pull them out so we could see, as distinct as their voices are, how integral union with Christ is to each.
I’ll admit John Owen can be difficult for modern readers to read. But it is not without reason that the word “Communion” is inscribed on his gravestone. Owen calls union with Christ “the greatest, most honorable, and glorious of all graces that we are made partakers of.” 33
Sinclair Ferguson, in his book The Trinitarian Devotion of John Owen, demonstrates that communion with God and union with Christ through the Holy Spirit is the great unifying theme of Owen’s works. For Owen, nothing is more practical to the Christian life than understanding this vital union and understanding that it is not abstract, but real and personal. Ferguson concludes:
Owen’s great burden and emphasis in helping us to understand what it means to be a Christian is to say: Through the work of the Spirit, the heavenly Father gives you to Jesus and gives Jesus to you. You have Him. Everything you can ever lack is found in Him; all you will ever need is given to you in Him … For the Father has “blessed us in Christ with every spiritual blessing in the heavenly places.” 34
Could anything be more helpful to your daily living and devotion to God than to realize this—that the Father sees you and all you do through the lens of your union and fellowship with Christ? 35
At the center of Jonathan Edwards’s theology is the idea that God’s own glory is the end for which God created the world and all things. Edwards says, “The beams of glory come from God, and are something of God, and are refunded back again to their original. So that the whole is of God, and in God and to God; and God is the beginning, middle and end in this affair.” 36 Edwards biographer George Marsden says, “That last sentence encapsulated the central premise of [Edwards’s] entire thought … Perfect goodness, beauty and love radiate from God and draw creatures to ever increasingly share in the Godhead’s joy and delight.” 37
That’s a remarkable statement from one of Edwards’s best readers. But it distills why, for Edwards, God’s glory and human happiness are not two differentiated things. True human happiness cannot be found or experienced apart from God’s glory. “Therefore God’s glory and human flourishing are one and the same.” 38
It is a beautiful dance: our highest joy is found in God’s glory, and God is most glorified in us when we find our highest joy in him. And it is at the cross of Christ that we see God’s glory most clearly because the cross is our best picture of who God is: God providing from within his own life the gift of bringing us back into his life. 39 For Edwards, this is the gospel—not any benefit that Christ brings, but that, above all, Christ brings us into communion with God. “The ultimate end of creation, then, is union in love between God and loving creatures.” 40 So it should not be surprising that Edwards did not hesitate to speak of our “participation in the life of God.” 41 It’s in this participation, this communion with God, that God’s glory and our highest joy fuel each other. And so Edwards concludes, “By virtue of the believer’s union with Christ, he doth really possess all things.” 42
Next we turn to Karl Barth, who is a controversial name in some quarters and unknown in others, but is still considered by many to be the most influential theologian of the twentieth century. Barth considered union with Christ to be “the principle controlling Christian existence … Whatever else may distinguish [the Christian life], it is to be understood primarily and decisively from this standpoint.” 43 It may be fairly said of Barth’s theology as a whole, “Not since the apostle Paul has one phrase [in Christ] so dominated a theologian’s work.” 44 And you can see this emphasis on the abiding importance of our union with Christ carried on, albeit in different ways, in the works of two theologians who were influenced by Barth, T. F. Torrance 45 and Dietrich Bonhoeffer. 46
Lastly for us, there is C. S. Lewis, sounding very much like the church fathers, whom he read widely, and with whom our historical-theological tour began. If, when you began to read this book, union with Christ sounded vaguely familiar to you, there’s a good chance it is through the influence of Lewis, who writes this of our union with Christ:
The whole dance, or drama, or pattern of this three-Personal life is to be played out in each one of us: or (putting it the other way round) each one of us has got to enter that pattern, take his place in that dance. There is no other way to the happiness for which we were made … Once a man is united to God, how could he not live forever? … But how is he to be united to God? How is it possible for us to be taken into the three-Personal life? … Now the whole offer which Christianity makes is this: that we can, if we let God have His way, come to share in the life of Christ. … The whole purpose of becoming a Christian is simply nothing else. 47
I’ve left out so many important voices for whom union with Christ was a crucial theme (Maximus the Confessor, Thomas Aquinas, Bonaventure, Julian of Norwich, Martin Bucer, Richard Baxter, John Bunyan, Thomas Boston, John Williamson Nevin, Charles Hodge—just to name a few), and I haven’t even touched on the Eastern church fathers or the Orthodox branch of the church, in which the idea of theosis has remained prominent. 48
But at the risk of getting lost in this crowd of theologians, I felt it was important to show beyond doubt that this theme of union with Christ, besides being biblically central, is also historically critical—that many of the formative voices of church history saw union with Christ as integral to understanding why the gospel is good news. I hope this chapter has convinced you how necessary it is for us to recover this forgotten jewel.
Before we conclude this chapter, I should note that union with Christ is making a comeback. There has been an explosion of interest in both theological circles 49 and academic circles. 50 My hope as a pastor, and my goal with this book, is to return union with Christ to the central place it held for much of Christian history—not as the province of scholars, but as a living reality, central to the life of all believers. This is what we are missing today, and nothing is more personally helpful, theologically significant, or pastorally needed than a recovery of union with Christ.
To answer our opening question: The heart of the good news is our union with Christ and our communion with God. It is the arc of the entire biblical narrative and the core truth of the whole Bible’s teaching concerning salvation. From the early church, through the centuries, and even now, theologians have agreed that the entirety of our relationship with God is captured in our union with Christ.
The question that follows then is this: Why would so many of us have a hard time recounting the practical and devotional significance of union with Christ? If John Murray is right that nothing is more central or basic, then why is union with Christ neither central nor basic in our understanding of what it means to be a Christian?
Whatever happened to union with Christ?