You are the salt of the earth. You are the light of the world.
Everyone likes salt and light, or at least everyone has to like it who wants to stay alive. It is not a question of high-sodium diets or artificial light pollution, but of basic human needs.
This immediately brings us to the point of the matter. Being salt and light may be needful, but it is no automatic popularity or happiness. We have what people need, but people very often need things that they do not want and want things that they do not need.
These are complex metaphors in the end. I wonder if the disciples on the mountain heard them, as we so often hear them, and found them unsurprising, maybe a little poetic, only to be struck later by their strangeness. You are the salt of the earth. You are the light of the world. Not “you should be like these things,” or “you should aspire to these things.” Jesus continues his instruction as the new epitome of the Law and the Prophets. Prophets speak truth, describing reality. If you are my follower, the Lord says, these things describe you. Light can illuminate and warm, but it can also blind and sear. It can be useful, or it can be merely decorative. Likewise, salt can preserve and flavor, but it can also kill.
Though many of these resonances are natural, others pertain more closely to the experience of Israel, above all to the Temple at Jerusalem. All sacrifices in the Temple were sprinkled with salt. As Remigius observes, “in the Old Testament no sacrifice was offered to God unless it were first sprinkled with salt, for none can present an acceptable sacrifice to God without the flavor of heavenly wisdom.” This association of salt with wisdom, or with knowledge, is taken up early on through the use of salt with holy water and baptismal water. “Receive the salt of wisdom,” we say to catechumens. The later medieval commentator Durandus delightfully describes wisdom as the “condiment of all virtues as salt is the seasoning of all foods.”
Light, too, has a close association with the Temple, which is constantly described by the prophets as a source of light. At the Feast of Tabernacles, the courts of the Temple were lit twenty-four hours a day by large menorahs that had to be lit by men climbing up on ladders. And Jerusalem is likewise a “city sat on a hill,” with the Temple itself being in the most prominent position.
The whole point seems to be that Jesus sees his disciples as somehow a living temple, replacing the old temple of stone. This idea takes on further weight when we look at the Lord’s claims about that temple being cast down, and about how his disciples will consume his body and blood—he who describes himself consistently in sacrificial terms as somehow embodying a new temple of God’s presence.
Being Christ’s disciples, we are this light, this salt, this temple. But here too we can see the double-edged sword of the metaphor. Just as salt and light can harm, the goodness of the Temple in fact did become, so often in the history of God’s people, a source of corruption and hypocrisy. How often do the prophets lament, as Isaiah does in today’s first reading, the failure of the people to act toward one another in a way consistent with their supposed devotion to God?
Our call as Christians is to follow the Christ who is the “light to enlighten the Gentiles,” as Simeon says at the Presentation. We inherit this mantle of Israel to be a kind of salt to the nations, preserving, seasoning, purifying, calling them to their true nature in the light of God.
Israel’s failures were, so often, the failures of light and salt. What salt and light have in common is that they do not draw attention to themselves, but reveal other things, enhance other things. You’re not really supposed to taste salt; you’re supposed to taste all the other good flavors that the salt brings out. Good lighting should reveal the beauty of a person, place, or thing; it does not draw attention to itself for its own sake.
Our Lord himself is salt and light, too, though differently, above all in the fact that he is the “light of the world” (John 8:12) in a more particular sense. His light reveals, and his salt flavors, but he, unlike us, is the main feature: the light of God is the end of all things. Yet by the Incarnation, and the communication of his divinity with human nature, we see the most profound example of that illuminating and salting work of grace within nature. It elevates and enlightens; it does not destroy. And in another way, the Lord is salt and light in a way that applies to us, if again differently: for salt and light give of themselves to do what they do. Salt can flavor food only by becoming itself food and being eaten. Christ’s “seasoning” of human nature, or “leavening,” if we can mix in another Patristic-scriptural metaphor, happens because he is “mixed up” with us, because he suffers with and for us.
Salt is meant to be used, just as a lamp is meant to be used. But to allow ourselves to be used for the glory of God means giving something. We cannot be salt simply by standing on the sidelines of the world and hoping we will give off a vibe while we go about our own private business. To season with our own lives, to shine light with our own lives, is a form of wisdom and knowledge that can only gesture, as St. Paul attests, to the cross of Christ.
As we continue moving toward Lent, the time is ripe to consider the works of mercy, and take an honest look in the mirror, following the exhortation of the prophet Isaiah. This is not a matter of some trying to calculate out how many good deeds you need to do to make up for the bad. That is exactly the sort of hypocrisy the prophets deplore. The question is, what story does my life tell? What truth does it reveal, and what truth does it obscure?
Our life as Christians is salt and light. Whether for good or ill, time will tell.