Salt and Light
In today’s gospel, Jesus presents two metaphors. He speaks to his followers about how they already are salt of the earth and light of the world. He explicitly addresses his followers in contrast with their counterparts in the synagogue.
Salt was a critical necessity in the ancient world. It was used for seasoning, preservation, and purifying. It was used to ratify covenants and in liturgical functions. To eat salt with someone signifies a bond of friendship and loyalty.
Salts in the soil are also needed to ensure its fertility so that it can produce a plentiful harvest, but soil that is “nothing but sulphur and salt” is a desert wasteland.
In telling his disciples “You are the salt of the earth,” Jesus can draw on any of these symbols. Disciples preserve, purify, and judge, drawing out the savor of God’s love in the world. The puzzle about how salt may lose its taste is probably best answered by salt being diluted or dissolved. Coming on the heels of Jesus’ exhortation to rejoice when persecuted, it is likely a warning to disciples not to let their ardor dissipate under the rigors of persecution.
Disciples are also “the light of the world,” like a city set on a mountain that cannot be hidden. This metaphor has a political twist since Cicero described Rome as a “light to the whole world.” It is Jesus’ beatific way of life that is light to the world, not the imperial domination system. Just as the city on a mountain cannot be hidden, a lamp is not lit and then immediately extinguished. One does not waste precious fuel oil this way. Using a vessel (e.g., a “bushel basket”) to put out the light would prevent dangerous sparks from spreading.
These two images speak of the all-encompassing nature of the witness of disciples: as salt and light they influence the whole world. These metaphors also show that the disciples do not draw attention to themselves. Just as salt is most effective when it is not noticed in well-seasoned food and a lamp serves to illumine the other objects in the room, so the effect of disciples’ good works is to point to God, who is glorified.
And that is what we are called to do as well. Just like the disciples, we are to be “the salt of the earth” and “the light of the world” for the glory of God.
(Based on Barbara E. Reid, “The Gospel according to Matthew,”, The New Collegeville Bible Commentary.)