Last week we were saying that the new law, promulgated by Jesus on the mountain, is a sui generis law: before being a code of precepts, it is a good news item. In the Beatitudes Jesus confines himself to declaring that the poor are blessed, that they are God’s favorites, regardless of their merits and holiness. If you remember, Saint Paul told us that God does not choose the best, the wise and the strong, but the foolish, the weak and the lowly, so that no one may boast before him. God’s election is totally free; it does not depend on our works. In the letter to the Galatians, Paul says: “By works of the law no one will be justified … if justification comes through the law, then Christ died for nothing” (Gal 2:16.21). For this reason, addressing the Corinthians—as we have heard in the second reading—he reminds them that “I resolved to know nothing while I was with you except Jesus Christ, and him crucified.”
But this does not mean that our behavior is irrelevant. What Luther said: Pecca fortiter, sed crede fortius (“Sin greatly, but believe still more greatly”) is false. If our works are worthless with regard to our first justification, they are indispensable as to our final salvation. That is why Jesus, in the Sermon on the Mount, just after declaring blessed the poor, reminds his disciples of their duty to do good deeds, not only to save their souls, but to save the world. To depict his disciples’ duty, Jesus uses two images: salt and light. “You are the salt of the earth (sal terrae) … You are the light of the world (lux mundi).” What does Jesus mean?
Salt can be used for two purposes. First of all, it serves as a condiment to give flavor to food. But, at the time of Jesus and until not so many years ago (when refrigerator did not yet exist), it was used also to preserve food. Well, Christians, with their behavior, should give flavor to the world and preserve it from decay. Jesus’ supposition of salt losing its flavor could seem unusual; but the salt coming from the Dead Sea, because chemically impure, could really lose its taste. Jesus hints at this possibility, to emphasize the risk for Christians of losing their identity and mingling with the crowd, following fashions and conforming themselves to the customs of the majority. What is the use of such Christians? The same as that of tasteless salt: “It is no longer good for anything but to be thrown out and trampled underfoot.”
Light does not change reality, but it allows us to see it and to move in it. We might be in a wonderful place; but, without light, we would not know it and we could not take advantage of its opportunities. The world is beautiful, because it was created by God; but, until it remains in darkness, it cannot be enjoyed; indeed, it is for us a source of danger. It is Jesus that brought light into the world; he said of himself: “I am the light of the world … I came into the world as light” (Jn 8:12; 9:5; 12:46). But he also wants us to be, like him, the light of the world. How? Behaving as he behaved; doing good deeds.
Even in this case, it could seem strange that Jesus says: “Your light must shine before others, that they may see your good deeds.” Below, in the same Sermon on the Mount, Jesus will urge his disciples not to perform righteous deeds in order that people may see them; now he seems to say the opposite. What are we going to do about it? Of course, we should not do good deeds to be seen by others, that is to say, to be praised by them. But we should not even hide ourselves. As Jesus says in today’s gospel, “A city set on a mountain cannot be hidden. Nor do they light a lamp and then put it under a bushel basket; it is set on a lampstand, where it gives light to all in the house.” We should be very simple in doing good: neither show off, nor hide ourselves. If we are light, we cannot but give light. What matters is the intention: not to win the praise of others, but so that people may glorify the heavenly Father.