Matthew 5:13–16: Salt and Light
In this chapter, Jesus offers a couple of metaphors for the Christian life.
The first metaphor is that of salt. Jesus says that his followers are “the salt of the earth” (verse 13 (ESV)), but then he asks a rhetorical question: if salt loses its saltiness, what is it good for? His answer to the rhetorical question is that it isn’t good for anything, except to be thrown out onto the road.
His next metaphor is that of light. Jesus says that his followers are “the light of the world” (verse 14 (ESV)). He says that when a city is on a hill it cannot be hidden (the light would be like a beacon), and when people light a lamp, they put it on a stand, not under a basket. (After all, what would be the point of lighting the lamp if you were going to hide the light under a basket? It wouldn’t make sense.) So, for this reason, he urges them to let their light shine before the others—he wants others to see their “good works,” and therefore “give glory to [their] Father who is in heaven” (verse 16 (ESV)).
Above I said that Jesus is talking about “the Christian life,” although, at this point, I guess there isn’t any such religion as “Christianity”—that will come after his death. Right now, there are Jews, who are following another Jew whom they believe may or may not be the Messiah. It probably doesn’t matter, and I’m probably just splitting semantic hairs; Jesus is talking about people who are saved (or going to be saved), regardless of whether they were yet calling it “Christianity.”
In the first metaphor, Jesus compares his followers to salt, and asks a rhetorical question about what you would do with salt if it lost its saltiness. Which, you might notice, is not physically possible, in and of itself—salt is salt; how can salt be less salty than salt, when it’s salt? The way it can become less salty is if it becomes impure, because it is mixed with other substances. In the Christian life, we might say that this other substance is sin; as Christians, we are the salt of the earth, but when we let sin pollute our souls, it makes us less salty (so to speak), because the sinfulness gets in the way of our godliness. (I can’t claim credit for this thought; I heard not one, but two sermons recently, which made this point about salt being polluted with other substances. If I remember correctly, one of the sermons mentioned that people in Jesus’ day would have kept their salt in some kind of cellar, where dirt would probably have gotten mixed in with the salt on a regular basis.)
In his next metaphor, Jesus compares his followers to light, and urges them to let their light shine before the world. The interesting thing to me about this metaphor is how it is worded; it’s simply taken for granted that light will shine; that’s what light does. The only way that light wouldn’t shine is if you purposely stopped it from shining (e.g. by covering it with a basket). If you don’t purposely try to stop the light from shining, it will shine. If I am a Christian, my light will shine before the world, they will see my good deeds, and they will glorify my Father in heaven. That is what will naturally happen. If it’s not happening, it must be because I’m stopping it from happening.
This may or may not be a problem that is very prevalent in North America; we live in a society with complete religious freedom, and do not have to worry about organized persecution for following Jesus—and yet, many, many Christians in North America are afraid of publicly letting their light shine, for fear of ridicule, or not fitting in. That is an oversimplification, but I stick by it nonetheless.
A final point I thought of on this passage is the reason that Jesus wants people to see our light: To give glory to our Father in heaven. He should get the glory; when I do something right, and people see it, and know that I’m doing it because I’m a Christian, their response should not be, “Wow, that’s a good man.” It should be more like, “Wow, what a God, who would enable a man like that to do good things.” Part of that would come from the way in which I do good works; I should do them such that I’m not seeking my own glory, but His. But part of that would also have to come from an explanation of the Gospel, so that they can understand what’s really going on. And sometimes it will come from both; if people tell me that they’re impressed that I did something good, it’s an opportunity to be able to tell them that, really, I’m a sinful man, and it’s only by the Grace of God that I’m able to please Him, and use that as a jumping off point to explain the Gospel.