Chapter 3

Matthew 5:13–16

LISTEN to the Story

13“You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot.1

14“You are the light of the world. A town built on a hill cannot be hidden. 15Neither do people light a lamp and put it under a bowl.2 Instead they put it on its stand, and it gives light to everyone in the house. 16In the same way, let your light shine before others, that they may see your good deeds3 and glorify your Father in heaven.”

Listening to the text in the Story: Genesis 1:26–27; Exodus 19:4–6; Psalm 8; Isaiah 51:4; 60:3; 61:6; Matthew 19:28; Romans 5:12–21 (esp. v. 17); 2 Timothy 2:8–13; 1 Peter 2:1–12; Revelation 1:5–6; 5:9–10; 20:4–6.

It is easier to think of salt and light as clever metaphors and then assume their meanings are clear to spin off into practical living exercises, than it is to think of the metaphors in the context of the Bible’s big Story. This text encourages us to reimagine our role in the world as God’s agents of redemption. Again, it is simpler to reimagine that role in this world as “moral influence” than through the biblical notion that is at work in the metaphors of salt and light. Because the moral-influence theory is instinctive for us, I have provided a long list of texts immediately below the citation of 5:13–16. I would urge you to read them all.

A brief sketch of those passages in the Bible assigns a particular role to Adam and Eve (Gen 1:26–27; Ps 8:1–6), then to Abraham (Gen 12), then through him to Israel (Exod 19:4–6), and eventually to Jesus and through him to his disciples as the church (Matt 19:28; 1 Pet 2:1–12). But this role is given to the church only after Jesus Christ has actually performed that role perfectly (Rom 5:12–21; 2 Tim 2:8–13). What role is this? The role of being both priests and kings on behalf of God in this world. A simple probing of the final kingdom reveals that God’s people will be mediating and ruling in the world in the kingdom (Rev 1:5–6; 5:9–10; 20:4–6). This conclusion to history leads us to a powerful and practical orientation in life: we are to mediate and rule now in light of the task we will be assigned in the kingdom.4 Again, we are looking at an Ethic from Beyond mediated to us through the ruling King Jesus.

Keep this front and center: our mediating and ruling roles are only done in Christ, who is the Mediator and Lord. In Christ we are assigned a role, and salt and light are dimensions of that role. Only once we are on the right road (mediating, ruling) can we grip the wheel and guide our vehicle through the metaphors of salt and light.5

EXPLAIN the Story

What is implicit in 5:13–16, and buried inside the “you are … ,” is that Jesus assumes his disciples will be salt and light because they are the followers of 4:18–22, the blessed of 5:3–12, and the obedient ones of 5:17–48 and beyond. They are not salt or light automatically but only to the degree that they “are” followers of Jesus.6 Furthermore, perhaps we should give emphasis to the “you” in “you are”7 because Jesus singles out his own followers and in so doing chooses against the standard Jewish options: they are the salt and light, not the temple, Jerusalem, the Torah, or the Pharisees. Paul knows that Israel thought it was the light to the world (Rom 2:17), but Jesus assigns this task exclusively to his followers as they indwell him who is the light of the world (John 8:12; 9:5; 13:35).

Both salt and light are images for impact on something else: salt impacts, for instance, meats, while light impacts darkness. While the specific sort of impact may not be clear, one would have to think both salt and light pertain to gospel teaching as well as to behavioral witness as impacting those who hear and see. Thus one can render these statements more actively as “You salt the earth” and “You enlighten the world.”

Salt of the Earth (Land)

When we examined the third beatitude (“Blessed are the meek, for they will inherit the land”), we suggested that the common translation “earth” or “world” was probably not in mind. The same applies here: it is unlikely that “earth” means “world” but instead translates Jesus’ use of the word “Land” ( ʾereṣ). Jesus is referring to the land of Israel. We will shortly also suggest that “world” in the second metaphor (“light of the world”) anticipates a Gentile mission. In other words, one metaphor (salt) speaks of the role of Jesus’ people to Israel and the other (light) to the Gentile world. The Israel-focused mission (the salt metaphor) is seen in Matthew at 10:5–6, 23, and 15:24. We might need to remember that there were two missions among the earliest followers of Jesus: one to Jews and one to Gentiles (see Acts 15:27–29; Gal 2:1–10).

Jesus’ concern in the salt metaphor is the potential of diminishing one’s impact, and so he crafts the metaphor of salt as one expressing negative possibilities. Thus, salt, if not treated properly or put to good use, will become insipid—“lose its saltiness”—and become good for nothing, or what John Stott calls “road dust.”8 The text is a poetic warning about judgment if one does not sustain one’s saltiness—that is, if one is not faithful.9

Scholars as well as preachers, students as well as readers, have vexed themselves in discerning in what manner the followers of Jesus are salty. Salt, which was obtained from the shores of the Dead Sea, was added to sacrifices and thus was covenant salt (Lev 2:13); salt purified things (Exod 30:35). Salt flavored things (Job 6:6), and seasoning is found in the parallel at both Mark 9:50 and Luke 14:34, and it was a preservative. Salt was a necessity of life. Furthermore, possibly carrying on a theme in the Beatitudes, salt was connected with peace and friendship (Mark 9:50; Col 4:6). The image begs its listeners to use its evocative powers for the various ways Jesus’ followers can influence their communities.

We are wise to avoid narrowing “saltiness” to only one sense; instead, we should use it as a general metaphor urging us to think carefully both about how we influence as well as the possibility of diminishing our influence. But we would also be wise to connect the sorts of influence we are to have to the themes of Jesus and, in particular, to the themes emerging from the Beatitudes (humble poor, pursuit of righteousness and justice, and creating peace and reconciliation). These would be the earliest “applications” made by followers of Jesus when they heard Jesus say they were the salt in Israel.10 Bonhoeffer said it well: “When Jesus calls his disciples ‘the salt,’ instead of himself, this transfers his efficacy on earth to them. He brings them into his work.” But he adds the warning of Jesus: “The call of Jesus Christ means being salt of the earth or being destroyed.”11

Light of the World

This second metaphor comes with a short paragraph that explores three different images that illustrate light impacting darkness: a city on a hill (whose lights are visible in the dark), a small terra-cotta oil lamp (which gives light in a dark room), and then light as a metaphor for good works. Lights are designed to shine; they are not to be hidden.

In the Bible and the ancient world light is connected to knowledge, truth, revelation, and love. It was not uncommon in the Jewish world to use the word “light” for people who passed on the light of God to others. A good example is Daniel 12:3: “Those who are wise will shine like the brightness of the heavens, and those who lead many to righteousness, like the stars for ever and ever.” But the image of “light” impacting darkness was connected to Israel telling of their God to the “nations” (Gentiles, world) in Isaiah. Here are two primary texts:

Listen to me, my people;

hear me, my nation:

Instruction will go out from me;

my justice will become a light to the nations (Isa 51:4).

Nations will come to your light,

and kings to the brightness of your dawn (60:3).

Here is where reading the Sermon on the Mount in light of the Bible’s Story reshapes both what we look for and what we see in the text. These texts suggest that “light of the world” is not a generic metaphor for moral influence in our local context, but actually anticipates the Gentile mission. With the general context of Israel’s light-bearing witness from Isaiah in our mind, we come to Matthew’s text to think again what he means by “you are the light of the world.” But before we even get to this verse, we bump into 4:14–16, where we find “Galilee,” “Gentiles,” as well as “light” and “darkness” by appealing once again to the same prophet, Isaiah. We have good reasons, then, to think that with “light of the world,” Matthew taps into this great theme from Isaiah. Here are the words from Isaiah 9:1–2 Matthew cites at 4:14–16:

Nevertheless, there will be no more gloom for those who were in distress. In the past he humbled the land of Zebulun and the land of Naphtali, but in the future he will honor Galilee of the nations [Gentiles], by the Way of the Sea, beyond the Jordan—

The people walking in darkness

have seen a great light;

on those living in the land of deep darkness

a light has dawned.

We suggest, then, that with “light of the world” in Matthew 5:14 Jesus is pointing to the Gentile mission when the gospel is taken beyond the land of Israel to the whole world.

Again, Jesus’ concern is with the inevitable impact of light in darkness. As a town full of lights cannot be hidden (and it is possible he means Jerusalem,12 but in Galilee one could see, for example, lights in Tiberias from Capernaum) and as people don’t light a candle and then put it under a bowl so that its light is snuffed out or at least diminished beyond value, so the disciples are to see the inevitability of their impact on the Gentile world.

The metaphor gives way to direct communication in 5:16: light means good works, or as the CEB has it: “the good things you do.” Jesus exhorts his disciples to be people of good works in a manner that attention and glory go to God the Father. Peter will later utter something similar about the impact of good works:

Dear friends, I urge you, as foreigners and exiles, to abstain from sinful desires, which wage war against your soul. Live such good lives among the pagans that, though they accuse you of doing wrong, they may see your good deeds and glorify God on the day he visits us. (1 Pet 2:11–12)

Works witness, but this gives rise to a subtle but soluble problem. Here Jesus summons his disciples to do things publicly in order to impact others, while in 6:1–18 Jesus pushes against doing things publicly to be seen. The difference is at the level of intent: in the latter, the intent is to be noticed and congratulated by others as someone who is righteous or pious, while here the act is to be done publicly but in order to mediate God’s redeeming presence in Christ and thus to glorify God. The paradox is deeper: in the brutal reality of Bonhoeffer’s own witness, he asked, “Is the cross not something which became outrageously visible in complete darkness?”13

LIVE the Story

Once we connect this passage to the Story of God and once we see the role of God’s people in that Story, this passage finds greater clarity. The text affirms our role as God’s priests and rulers. Jesus seeks to clarify that role by using the metaphors of salt and light.

Discipleship Means Mission

We can dispute the precise connotations of both salt and light, and we can dispute whether one refers to the disciples’ mission to Israel and also to the Gentiles. But one thing cannot be disputed: the follower of Jesus is summoned into a mission on behalf of and for God in this world. Salt and light both evoke the impact a follower of Jesus is to have on others.

Impact results from being missional, and it might be good for us to remind ourselves of a trend in contemporary theology, namely, to see the church and therefore individual Christians as missional. The fundamental insight here derives from the studies of theology on the part of missionaries and missiologists who spoke long ago of the missio Dei, or the mission of God. What we have to ask is not so much what our mission is but what God’s mission is. I prefer to express this in this way: God’s mission is to redeem a broken creation (as a result of sin and disobedience) through the life, death, resurrection, and exaltation of Jesus, through the gift of the Spirit to God’s people, in order to bring creation into its perfect order. Of course, we speak here of God’s final kingdom, but the challenge of God’s people is to live into that kingdom now.

Once we grasp the bigness of this mission of God, we are led to see the church not so much as having one dimension of its duties wrapped up under the heading of “Mission,” which more or less means evangelism. The church’s mission is God’s mission given to the church. A possible indicator of how we understand “mission” can be examined by looking at the church budget to see if the item called “Mission” is only about outreach. Instead, the church is missional. The church, in its very being and in everything it does, is missional: it is caught up in God’s mission. This theology has been cleverly captured in this expression: because God has a mission, there is a church.

I was invited to speak at New Covenant Fellowship in Champaign, Illinois, one weekend. What Kris and I encountered there is perhaps the most missional church I have ever experienced. A friend of ours who is part of this fellowship said to me that they were missional before they knew what that meant! The only way I can describe this church is to say the boundaries between church and community are porous. The church is an offering to the community and the community seeps into the church. There are no real “members”; those who attend are part of the fellowship, those who participate can participate as the Lord leads, and any and all are welcome to their services and their serving.

A contrast might help. For many of us our church, whether it tries to or not, creates a serious boundary between those who are “in” and those who are “out.” New Covenant has no such boundary. What New Covenant does is to minister to the local community—and we experienced some homeless folks, a middle-aged woman who showed signs of schizophrenia, some Jewish neighbors who thought the topic of my teaching was of interest to them—and whatever the local community needs is what shapes what New Covenant does. The church has become an open table—everyone is welcome to come hear about Jesus, to worship God, and to participate as each one desires. New Covenant wants to do in Champaign what God wants done in Champaign. They don’t care who does it; they don’t care what it takes; they want to participate in God’s mission.

The Story and the salt and light metaphors reveal that the church’s fundamental task is to mediate God’s presence as priests and to rule on behalf of God as kings and queens under God, serving God in God’s mission. Our task is to represent God—to mediate God’s goodness, God’s grace, God’s holiness, and God’s justice to this world as those who represent God. Salt and light, then, are about not just what we do but who we are.

Mission Includes Both Jews and Gentiles

Many Christians today, and I mean across the entire spectrum, want a Jesus who is as Jewish as one can make him. I once heard a veteran Jesus scholar say we are all trying to “out-Jewish-Jesus one another.” This orientation arose after the discovery of the Dead Sea Scrolls, in reaction to the German history of religions school’s emphasis on Greek and Roman religious influences on the New Testament authors, and through the brilliant work of New Testament scholars who illuminated the messages of both Jesus and Paul. One can say there is a fascination with all things Jewish. I have sketched a way of reading the salt and light metaphors in that context, but it is not enough to anchor Jesus into a credible Jewish world. His Jewishness has a missional intent.

Jesus’ summons to his disciples was to embody the kingdom vision so thoroughly that both Jews and Gentiles would see the behavior of his followers. In fact, they were to impact both Jews and Gentiles and were to draw both of them into praise of his Father.

This mission to Jews and to Gentiles requires both a behavioral and a verbal mission. The behavioral refers to “good works,” and in that world it would have meant almsgiving, visiting the sick, showing hospitality to foreigners, helping a newly married poor couple outfit a new home, sharing expenses and provisions for a wedding or funeral, and grieving with the suffering.14 In our day it can take on even more forms, like caring for the suffering in Haiti, establishing hospitals for those with AIDS, providing compassion and guidance for the undocumented, funding food, provisions, and education for orphans, as well as helping in a local food pantry. Each and any other kind of behavioral compassion is a way of being both “salt” and “light.” Nothing goes straighter to the heart of those in need like love.

Works witness, but those with such works are to witness to Jesus Christ as well. Some today are fond of the word missional because it may let them get off the hook of evangelism. The word is far more robust than that, and that is why so many (including this writer) are in favor of it. But behavior is not enough. The only way Jesus’ Jewish context or the later Gentile context can be people who “glorify your Father in heaven” is to know the connection of the behaviors to the God who summons them. In other words, the behavior of the missional follower of Jesus leads the missioner to witness to Jesus Christ and to the Father. John Dickson’s new book about promoting the gospel15 provides an exceptional balance in this discussion. He is right in emphasizing that not all are called to be constant verbal evangelists, but we are all called to promote the gospel with our deeds, with our money, with our church, and with our words.

And our text calls us to promote the gospel to all, both Jews and Gentiles. Since missional work with Gentiles is the most common, I will ignore this aspect and focus on missional work with Jews. I spent more time than I care to admit doggedly reading and cataloguing Jewish conversion stories, the most recent and popular of which is Lauren Winner’s must-read Girl Meets God,16 and I’d like here to deposit conclusions from that study.17 It begins with the observation that in our world, post-Holocaust and post-centuries of Christian anti-Semitism, conversion from Judaism to Jesus Christ (or the church) involves a challenge to the very identity of a Jew in a way perhaps unparalleled in any other kind of conversion. This is a standard Jewish perception: to be Jewish is not to be Christian; to be Christian is to betray one’s Jewishness. That is the context for contemporary Jewish conversion, and it makes the move for the Jew anguishing.

While some Jews convert to Jesus Christ—and become messianic Jews—because of the power of a charismatic figure, because of some psychological healing, because of a tragedy, because of a mystical experience, or simply because of a general dissatisfaction in life, the most important factor involved in a Jewish conversion is something that Gentiles almost never consider. The fundamental issue is that Jews must be convinced that Jesus is the Messiah. So, nearly every Jew who converts to Christ becomes a student of Jewish Scriptures, particularly the Prophets, to see if what those Scriptures say about the Messiah matches what we know about Jesus. Once this examination is complete, and once one concludes that Jesus fits the bill, the process of conversion is already over. That admission makes the person a follower of Jesus.

Alongside this fundamental issue is one that follows: once a Jew becomes convinced that Jesus is the Messiah, that same Jew develops the belief that forgiveness of sins comes to them through Jesus’ death and resurrection. Notice the order: the typical Jewish converts I have studied rarely are in a quest to find forgiveness of sins, and I believe this is because Jews have a robust belief in atonement, and they enact it and participate in it every year at Yom Kippur, the Day of Atonement. So, the problem for a Jew is not the need for forgiveness but whether or not Jesus is the Messiah. If Jesus is the Messiah, then forgiveness comes through him. So, my own wisdom for missional work among Jews is to live a life of love and justice and to learn the Prophets well enough to provoke questions among Jewish friends about whether Jesus is the Messiah. The rest will follow.

I make only one more point: it is unnecessary to require Jews to surrender their Jewishness in order to convert to Jesus as the Messiah. The earliest followers of Jesus were Jews, and they did not cease being Jews when they converted but became messianic Jews, or Yeshua-following Jews. There’s so much more to say here, but this should suffice.18

Danger of Diminishment

This passage comes with a powerful warning, and that warning concerns diminished witness. Jesus uses a metaphor here: when salt loses its saltiness, it is tossed aside for road grit. With light Jesus speaks less about judgment and more about the incomprehensibility of something being lit and then covered so that the light’s value is undone. But the image of being “thrown out” uses a word that is connected to judgment in Matthew’s gospel:

Jesus’ language is shaped to warn the followers of Jesus of the consequences of diminishing their impact: saltless salt is thrown away and covered lights are useless.

With this as our basis, we can consider the implications for us: to live this Story today we must take to heart what Jesus says. If we damage the impact we already have, that impact may never be regained (as is the case with some leaders who have fallen, with parents who have sacrificed their integrity in a family or neighborhood through morally reckless behaviors, etc). What’s worse, Jesus evidently warns of judgment. I am less concerned here with the Calvinist-Arminian debate on whether or not a person can “lose his/her salvation” than I am with the rhetorical power of the image Jesus uses. Consequences follow in the Story of the Bible for those who are unfaithful to God’s covenant blessings, and we can begin with the implicit warning of God walking between the cut up animals in Genesis 15, the blessings and curses of Deuteronomy 28, the sad collapse of leaders like Saul and Solomon, the diminished leadership of David, and the exile of both the northern and the southern kingdoms into Assyria and Babylon, respectively.

Instead of dwelling on the debatable, the text ultimately guides us to think about the need to be faithful—and again the Story of the Bible gives us powerful examples of covenant faithfulness, like Joseph, Moses, Joshua, Ruth, David, Isaiah, and Esther, and like Mary, Jesus, Paul, Peter, and Junia. No one is perfect, but all are called to remain faithful to Jesus.

1. KNT: “You might as well throw it out and walk all over it.”

2. KNT: “bucket.”

3. KNT: “what wonderful things you do.”

4. I disagree, then, with the classic view of John Stott that this refers to our evangelism and social action, even if I agree with him on the relation of these two and their fundamental importance in Christian witness; see his Message, 57–68. For a diamond-cutting discussion of this theme in Stott’s career, see J. Greenman, “John R.W. Stott,” in The Sermon on the Mount through the Centuries (ed. J. P. Greenman et al.; Grand Rapids: Brazos, 2007), 266–79. Greenman’s conclusion resonates with my own experience of the same time period.

5. For discussion, see Wright, After You Believe, 73–100.

6. W. D. Davies and D. C. Allison Jr., A Critical and Exegetical Commentary on the Gospel according to Saint Matthew (ICC; 3 vols.; Edinburgh: T&T Clark, 1988), 1:471.

7. Note that in the Greek of vv. 13 and 14, “you” is emphatic.

8. Stott, Message, 60.

9. Kinghorn, Wesley on the Sermon, 111–13.

10. Luz, Matthew 1–7, 208; Keener, Matthew, 172–73.

11. Bonhoeffer, Discipleship, 111–12.

12. Isa 2:2–3; Ezek 5:5. That Jerusalem is in mind is a common observation: see, e.g., Garland, Reading Matthew, 59.

13. Bonhoeffer, Discipleship, 114.

14. If one can read German, there is an exceptional sketch of Jewish information in H. Strack and P. Billerbeck, Kommentar zum Neuen Testament (Munich: C.H. Beck’sche Verlagsbuchhandlung/Oskar Beck, 1928), 4.1.559–610.

15. J. Dickson, The Best Kept Secret of Christian Mission: Promoting the Gospel with More than Our Lips (Grand Rapids: Zondervan, 2010).

16. Lauren Winner, Girl Meets God on the Path to a Spiritual Life (Chapel Hill, NC: Algonquin, 2002).

17. You can find this study in ch. 2 of my Finding Faith, Losing Faith (with Hauna Ondrey; Waco, TX: Baylor University Press, 2008), 65–122.

18. I recommend Dan Cohn-Sherbok, Messianic Judaism (New York: Cassell, 2000), and M. S. Kinzer, Post-Missionary Judaism (Grand Rapids: Brazos, 2005); D. Rudolph and J. Willitts, eds., Introduction to Messianic Judaism: Its Ecclesial Context and Biblical Foundations (Grand Rapids: Zondervan, 2013).