Matt 5:13–16 — Salt And Light In the World

Jesus has just concluded the Beatitudes, which describe the character and blessedness of those who belong to the kingdom of heaven. The disciples are poor in spirit. They mourn over their sin and the brokenness of the world. They are meek, hunger and thirst for righteousness, show mercy, pursue purity of heart, and make peace. They are also persecuted for righteousness’ sake and on account of Christ.

Jesus now turns from those descriptions to the disciples’ relationship with the world: “You are the salt of the earth” and “You are the light of the world.” These verses must be understood in connection with the Beatitudes. As we live out the righteousness of the kingdom described there, we become salt and light to those around us.

Jesus does not say, “You ought to become salt,” or, “You should try to become light.” He says, “You are the salt of the earth” and “You are the light of the world.” This is the identity of those who belong to him. Yet the warnings and commands that follow show that we must live consistently with that identity. Salt must retain its taste, and light must not be hidden.

We will consider the salt of the earth, the light of the world, and then ask how we fulfill this calling and to what end.

The Salt of the Earth

“You are the salt of the earth,” Jesus says, “but if salt has lost its taste, how shall its saltiness be restored?” What does the metaphor of salt mean?

Salt as Seasoning

Two interpretations are common. Some understand salt primarily as a preservative. Before refrigeration, salt was used to keep food from spoiling. On this reading, Christians preserve a corrupt world and slow its moral decay. That interpretation is possible as a general truth, but nothing in the immediate context points specifically to preservation. Jesus focuses instead on salt’s taste: “If salt has lost its taste.”

It is more natural, then, to adopt the second interpretation—salt as seasoning. Luke’s parallel supports this. Luke 14:34 says, “Salt is good, but if salt has lost its taste, how shall its saltiness be restored?” The question may also be rendered, “With what will it be seasoned?” Paul uses the same familiar association in Colossians 4:6: “Let your speech always be gracious, seasoned with salt.” Salt brings out flavor and makes food pleasing.

Jesus is therefore saying that his disciples bring a distinctive flavor into the world. Their poverty of spirit, meekness, mercy, purity, peacemaking, and willingness to suffer for righteousness stand out in a world governed by pride, self-assertion, revenge, impurity, and hostility.

Yet the Old Testament gives the salt metaphor an additional dimension. Leviticus 2:13 says, “You shall season all your grain offerings with salt. You shall not let the salt of the covenant with your God be missing from your grain offering; with all your offerings you shall offer salt.” Salt was associated with the offerings God’s people presented in worship.

These grain offerings were not sacrifices that atoned for sin. They were offerings of worship, thanksgiving, and dedication. Salt belonged to the covenant offering placed before God.

We should therefore hold together two ideas: flavoring and offering. Jesus addresses his disciples not merely as isolated individuals but as a corporate body. Together, as a worshiping community, they are the salt of the earth. Their life before God gives a distinctive flavor to their witness before the world.

This interpretation also fits the parallel image of light. Jesus explains that others will see the disciples’ good works and glorify their Father in heaven. To be salt is to bear witness to the unbelieving world through a life offered to God.

When Salt Becomes Tasteless

The statement that salt can lose its taste sounds strange to us because modern table salt is highly refined. In the ancient world, however, salt was often mixed with other minerals. The actual salt could be leached away, leaving behind a residue that looked like salt but had none of its taste.

The Greek expression translated “lost its taste” literally means “become foolish.” Tasteless salt is insipid. It has no distinctive quality and nothing that stands out. This literal wording connects moral and spiritual foolishness with the loss of Christian distinctiveness.

This is the great problem with progressive Christianity understood as a continual accommodation to the dominant culture. Its advocates want Christianity to remain relevant by removing whatever the world finds objectionable. Yet the more fully the church adopts the world’s assumptions, the less it has to offer. In the effort to become relevant, it becomes irrelevant. The modernist impulse is, in the deepest biblical sense, foolish: the salt becomes tasteless.

Jesus asks, “How shall its saltiness be restored?” The rhetorical question seems to imply that it cannot. Literally, he asks, “With what will it be salted?” If the salt itself has lost its savor, what else remains to provide seasoning? If the church no longer has Christ and his gospel at its center, what can give it spiritual flavor again?

Jesus continues, “It is no longer good for anything except to be thrown out and trampled under people’s feet.” We should not turn every feature of this metaphor into an allegory. He is not giving a detailed account here of the loss of salvation. People throw worthless residue onto the road, where it is walked upon, because it no longer serves its intended purpose.

The warning is nevertheless serious. If Christians become indistinguishable from the world, they lose the value of their witness. The Lord does not call us to become good for nothing, fit only to be discarded as waste. He calls us to retain the distinctive savor that comes from Christ and the righteousness of his kingdom.

The Light of the World

Jesus changes the metaphor but continues the same basic thought: “You are the light of the world. A city set on a hill cannot be hidden.”

A City Set on a Hill

The city is more than a convenient illustration of visibility. Jesus is again addressing the disciples as a community. An individual lamp gives light within a house, but a city consists of many people gathered into one society. At night, a city elevated on a hill would be visible from far away as its lights shone in the darkness.

The city on a hill is not the Massachusetts Bay Colony of 1630, nor is it the United States of America. Jesus is not assigning a redemptive mission to a civil nation. The city is the community of his disciples—the church he later promises to build: “I will build my church” (Matt 16:18).

Jesus continues, “Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house.” The purpose of a light is to shine. No one lights a lamp and then covers it. The “house” in this image represents the sphere in which the disciples live, including the unbelievers who observe them. Christ gives light to his people so that it may be seen.

Christ himself is the light of the world. He says in John 8:12, “I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.” We have no independent light. We shine only through union with him.

Paul makes the same point in Ephesians 5:8: “At one time you were darkness, but now you are light in the Lord. Walk as children of light.” He does not merely say that we once lived in darkness. We were darkness. Now we are light—but only “in the Lord.” Our identity and our calling both come from Christ.

Letting Our Light Shine

How do we let our light shine? Jesus answers: “That they may see your good works.” But which good works does he have in mind?

He cannot mean that every righteous act must be displayed publicly. In the next chapter, Jesus warns us not to practice righteousness before others in order to be seen by them. When we give to the needy, we should not sound a trumpet but should give in secret (Matt 6:1–4).

The difference lies in the purpose. We must never perform good works to attract praise to ourselves. Yet the life of a disciple cannot be completely hidden. As we live out the Beatitudes—as people who are humble, merciful, pure, peaceable, hungry for righteousness, and faithful under persecution—the character of Christ’s kingdom becomes visible.

There is also a corporate dimension. Jesus speaks of a city, not merely a collection of unrelated lamps. The church as a community shines before the world. Each congregation should be an outpost, or colony, of heaven: a visible society ordered by allegiance to Christ and by the life of the coming kingdom.

How, and to What End?

We have seen that Christians are salt and light both individually and corporately. We must now ask how this witness occurs and what goal it serves.

Christ in the Christian

The focus must remain on Christ and therefore on Christ-ians. We are salt and light only in him.

Individually, Christ is your life. Christian distinctiveness does not mean being strange merely for the sake of being strange. I grew up in an Assembly setting, where there could sometimes be an emphasis on being different from the world. Such distinctiveness can become external and artificial if it is detached from Christ. Peculiarity by itself is not holiness, and eccentric behavior is not a witness to the gospel.

Let Christ and his gospel provide the salt. Remember who you are in him, and express that identity in your life. Do not conceal the fact that you are a Christian. Let others know that you belong to Christ, and then live in a way that brings honor to him and displays the power and effectiveness of his grace within you.

The light is not our personality, our cultural preferences, or an effort to appear unusually religious. The light is Christ reflected in the ordinary faithfulness of his people.

The Church as a Worshiping Community

Corporately, we are the body of Christ. It is important not only to acknowledge that you are an individual Christian but also to identify yourself as a member of Christ’s church. The city on the hill becomes visible as believers gather to worship God through Christ, confess their common faith, and hear the Word of Christ.

The church’s worship is prophetic. This does not mean that worship should be redesigned as an evangelistic performance aimed primarily at unbelievers. Worship is directed to God. Yet precisely as the church worships the true God through Christ, its worship bears witness to the world.

Pliny the Younger, a pagan Roman governor in the early second century, described Christians in a letter to Emperor Trajan. He reported that they met on a stated day before dawn and sang a hymn to Christ “as to a god.” He also observed that they bound themselves not to commit theft, robbery, or adultery, not to break faith, and not to withhold money entrusted to them.

Pliny did not understand Christian theology, but he could see two things. These believers refused to worship Caesar as Lord and instead worshiped Christ as Lord. Their worship also committed them to upright living. The church’s confession and conduct together made it a city on a hill.

This is how a congregation serves as an outpost of heaven. It gathers in allegiance to the risen Christ, worships him as Lord, receives his Word, and lives according to the righteousness of his kingdom. The watching world encounters a community whose worship and life point beyond the present age.

Witness, Not Cultural Redemption

What is the goal of this salt-and-light calling? Some interpreters begin with the preservation view of salt and develop a broad program of cultural preservation or renewal. One writer describes disciples as “a preservative in the dying carcass of the world.” Don Garlington rightly prefers the biblical image of resurrection rather than the preservation of a carcass. He speaks of the restoration of God’s very good creation and describes Christians as instruments in lifting the curse and advancing the world’s eschatological redemption.

That language, however, gives Christians a task that belongs to Christ. We cannot redeem or renew creation. First, we do not possess such power. Second, redemption is the work of Christ, who died and rose again and who will make all things new at his return.

What would cultural redemption by the church mean beyond bearing faithful witness? Does it mean that our cultural products pass through the final judgment into the eternal state? Does it mean constructing a Christian nation? Jesus gives no such program in this passage.

Our calling is to be the worshiping church, the body of Christ, as a witness to the reality of Christ. The light metaphor explains the salt metaphor: “Let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.” The aim is that unbelievers might repent, come to faith, and join the church in worshiping the Father through the Son.

The Prophetic Witness of Worship

The Old Testament patriarchal altars help bring these themes together: salt, offering, and the city on a hill. The church at worship is a witness to the world, just as the patriarchs’ worship testified prophetically in the land of Canaan.

Genesis 12 records God’s call of Abraham and the promise to give the land to his offspring. When the Lord appeared to Abraham and announced the promise, Abraham built an altar and called upon the Lord’s name. The promise implied that the Lord owned the land and would establish his kingdom there, even though “the Canaanite was then in the land” (Gen 12:6).

Abraham therefore had to trust God’s promise in the face of contrary appearances. The Canaanites occupied the land, yet Abraham built altars to the Lord. Those altars had a prophetic function. They declared that the true God would establish his kingdom in the land amid the nations. They also warned of coming judgment in the conquest and called idolaters to turn to the Lord.

The church’s worship has a similar prophetic character. Every Lord’s Day, congregations gather throughout the world and confess that Jesus Christ is Lord. They announce that the kingdoms of this world belong ultimately to him and that he will return in judgment and salvation. Their worship calls the nations to abandon idols and give glory to the Father.

Hebrews 13:10 says, “We have an altar from which those who serve the tent have no right to eat.” Through Christ, the writer continues, “let us continually offer up a sacrifice of praise to God, that is, the fruit of lips that acknowledge his name” (v. 15). We no longer bring the grain offerings of the old covenant, seasoned with literal salt. Through Christ, we offer the worship and praise of the new covenant.

As we gather around Christ, confess his name, hear his Word, receive his sacraments, and live out the righteousness of his kingdom, we are the salt of the earth and the light of the world. We do not draw attention to ourselves. Our purpose is that others may see the fruit of Christ’s work in us and “give glory to your Father who is in heaven.”