Matthew 5:13-16

Bird's-eye view

Having laid out the foundational character of the kingdom citizen in the Beatitudes, the Lord Jesus now turns to the function of that citizen in the world. He does not describe what His disciples ought to be, but rather what they already are by virtue of their union with Him. They are not called to become salt and light; they simply are salt and light. The metaphors are potent and direct. Salt is a preservative, an agent that staves off corruption and adds savor. Light is that which dispels darkness and reveals what is true. Both metaphors point to a profound, world-altering influence. This influence is not optional, nor is it intended to be private. It is the natural outworking of a supernaturally transformed life. The central thrust of this passage is that Christian identity has an unavoidable public consequence. The world is decaying and dark, and Christians are God's appointed remedy for both conditions. The failure to be what we are is not just a failure, it is a contradiction that results in uselessness and contempt.

The passage moves from identity to responsibility. If you are salt, you must be salty. If you are light, you must shine. This is not a call to manufacture something artificial, but rather to live out the reality of the new birth. The purpose of this public, influential life is not to draw attention to ourselves, but to direct all attention and glory to our Father in heaven. The good works of believers are intended to be a signpost pointing a lost world back to the source of all goodness. This section, therefore, serves as a crucial bridge between the internal character of the believer (the Beatitudes) and the external righteousness that Christ will go on to describe throughout the rest of the sermon.

Outline

Context In Matthew

This passage comes directly after the Beatitudes (Matt 5:3-12), which describe the blessed state and inner character of those who belong to the kingdom of heaven. It is no accident that Jesus moves immediately from character to influence. The kind of person described in the Beatitudes, the poor in spirit, the meek, the merciful, is precisely the kind of person who will function as salt and light. The world expects influence to come from the proud, the powerful, and the self-sufficient. Jesus turns this completely upside down. It is the humble, dependent, God-fearing disciple who will truly change the world.

Furthermore, these verses set the stage for the next major section of the sermon, where Jesus discusses the law (Matt 5:17-48). By establishing the Christian's role as an agent of preservation and revelation, Jesus prepares His disciples to understand that their relationship to the law is not one of mere external conformity, but of a deep, internal righteousness that shines forth in a way that fulfills the law's true intent. The saltiness and light of the believer are the visible evidence of a righteousness that exceeds that of the scribes and Pharisees.

Clause-by-Clause Commentary

v. 13 “You are the salt of the earth; but if the salt has become tasteless, how will it be made salty again? It is no longer good for anything, except to be thrown out to be trampled under foot by men."

"You are the salt of the earth" - Jesus begins with a statement of fact, not a command. He is not telling His disciples to try to become salt; He is telling them what they are. This identity is a given, established by God's grace. In the ancient world, salt was essential. It was a preservative, preventing meat from rotting. It was a seasoning, giving flavor to food. It was also used in sacrifices as a symbol of the covenant (Lev. 2:13). Christians, then, are God's preserving agent in a decaying world. The culture, left to itself, will putrefy. Christians, by their very presence and influence, are meant to arrest that decay. They are also to provide the world with its true flavor, the savor of God's kingdom.

"but if the salt has become tasteless" - Here is the warning. While pure sodium chloride cannot lose its saltiness, the salt used in that day was often impure, mixed with other minerals. It was possible for the salt to be leached out, leaving behind a worthless, salt-like powder. The danger for the Christian is not that he can lose his salvation, but that he can lose his distinctive, preserving, flavorful influence. This happens through compromise, through worldliness, through fear of man. When a Christian ceases to be distinct from the world, he becomes useless to the world. He is no longer functioning as salt.

"how will it be made salty again? It is no longer good for anything" - The question is rhetorical and the answer is stark. There is no remedy for salt that has lost its savor. It cannot be re-salted. Its purpose is gone. A Christian who has compromised his distinctive witness has become functionally useless. He is not good for the church, because he brings the world's corruption in. He is not good for the world, because he offers nothing different from what it already has. This is a severe warning against cultural accommodation and syncretism.

"except to be thrown out to be trampled under foot by men." - The consequence is contempt. The world does not respect Christians who are just like them. It despises them. A believer who tries to curry favor with the world by hiding his saltiness will find that the world, once it discovers his hypocrisy, will not pat him on the back. It will walk all over him. Uselessness invites contempt. This is a picture of utter rejection, not just by God, but by the very world the compromised Christian was trying to impress.

v. 14 “You are the light of the world. A city set on a hill cannot be hidden;"

"You are the light of the world." - Again, this is a statement of identity. Jesus Himself is the true Light of the world (John 8:12), but believers, in union with Him, share in this attribute. As the moon reflects the light of the sun, so Christians are to reflect the light of Christ to a world lost in darkness. Darkness in Scripture represents ignorance, sin, and despair. Light represents truth, righteousness, and hope. The church, collectively, and believers, individually, are God's designated luminaries. Our function is to shine.

"A city set on a hill cannot be hidden" - The metaphor shifts slightly to emphasize the public and visible nature of our witness. A city built on a mountaintop is visible for miles around, day and night. It is an unavoidable landmark. In the same way, the church is meant to be a visible, public entity. Her life, her worship, her standards, her joy are all meant to be on display. The idea of a secret, hidden, private Christianity is a contradiction in terms. Our faith has public implications, and we are not to shy away from that reality. This is an ecclesiological statement. The gathered people of God are this city.

v. 15 "nor does anyone light a lamp and put it under a basket, but on the lampstand, and it gives light to all who are in the house."

"nor does anyone light a lamp and put it under a basket" - Jesus now uses a homelier illustration to make the same point. No one in their right mind goes to the trouble of lighting an oil lamp only to immediately hide its light. That would be absurd; it defeats the very purpose of the lamp. The "basket" here refers to a common household measuring bowl. To place it over a lamp would be to negate its function entirely. The application is sharp: for a Christian to hide his faith, to keep his good works private out of fear or a false sense of humility, is just as nonsensical. God did not light the lamp of your new life for you to hide it.

"but on the lampstand, and it gives light to all who are in the house." - The proper place for a lamp is on its stand, where it can fulfill its purpose of illuminating the entire room. The purpose of light is to be seen, and in being seen, to enable others to see. The Christian's witness is not just for his own benefit, but for "all who are in the house." This refers to our immediate sphere of influence, our families, our workplaces, our communities. Our light is meant to have a broad and beneficial effect.

v. 16 "Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven."

"Let your light shine before men" - Here, finally, is the command that flows from the identity. Because you are light, you must let that light shine. This is not a call to be obnoxious or to engage in spiritual showboating. Jesus condemns that kind of hypocrisy later in this same sermon (Matt 6:1-6). Rather, it is a call to live an open, honest, and unashamed Christian life in the public square.

"in such a way that they may see your good works" - How does the light shine? Through our good works. This is crucial. The light is not our pious talk, our bumper stickers, or our theological arguments, though those have their place. The light that the world sees is the tangible evidence of our faith in action. It is our integrity in business, our love for our enemies, our care for the poor, our joyful family life, our steadfastness in suffering. These are the works that make the gospel plausible to a watching world.

"and glorify your Father who is in heaven." - This is the ultimate purpose of it all. The goal is not that men would see our good works and glorify us. The goal is that they would see our good works and be pointed beyond us to the one who is the source of those works, our Father in heaven. Our lives are to be an advertisement for the goodness and glory of God. When a non-believer sees a Christian act with supernatural grace or integrity, the intended response is for them to think, "The God of that man must be a great God." Our good works are the evidence, but God the Father is the conclusion. Our lives are the sermon, and the doxology is the point.