We are not to become corrupted by any other influences. We are the salt of the earth. But salt has one other characteristic, a characteristic that it shares with all other elements of God s creation, and a characteristic highlighted by the next two metaphorical descriptions of the disciples. Salt is the way it is because that is what it is. Salt doesn t become salt by anything that it does, or by the manipulation of some outside force.
Salt is salt.
It can never serve as a sweetener for coffee. It can never be ground up and made into bread. It serves its function by being what it is. And its function is described by Jesus in the words that follow. You are the light of the world.