"You are the salt of the earth, but if salt has lost its taste, how shall its saltiness be restored? It is no longer good for anything except to be thrown out and trampled under people's feet. You are the light of the world. A city set on a hill cannot be hidden. Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven." (Matthew 5:13-16 ESV)
What did Jesus mean when he told his followers they were the salt of the earth? Do they make food taste better? Probably not. Do they make people have high blood pressure? At times, no doubt. But to catch his meaning, we must understand salt the way the first people who heard him say these words understood it.
Salt in those days was used primarily as a preservative. If a family killed a goat to eat, but couldn't eat it all in one meal, they didn't want to throw the rest of it out, and they couldn't put it in the refrigerator. So they rubbed salt into the meat, and it killed germs and put the brakes on spoiling and decay.
This pictures a somewhat passive role the followers of Christ have in the world. Our behavior should be such a witness that it arrests the moral decay of our society. Think of a group of teens telling dirty jokes when a preacher they know suddenly approaches. His presence has an immediate effect on their behavior. Such should be the influence of all who follow Christ. As salt is different in its very essence from the meat to which it is applied, so should the Christian offer a stark contrast in the way he conducts himself. The more the Christian becomes like the world, the less saltiness he has, and the less effective he is.
To be the light of the world is to have a more active influence. This involves sharing specifically with others how to find salvation. As light shines on the path to guide someone, so do we explain specifically to the lost one how he is to find heaven and avoid hell.
Salt and light, as Jesus used the terms, should always go together. Some prefer to be only salt. "I let my life be my witness," they say. And one's life should testify loudly, but not alone. They should be light as well by actively speaking in specifics about how to be saved.
Others prefer to be only light. Their pious words are many, but nothing about their lives inspires a desire to be like them or to have what they have.
But salt and light working together in the life of a believer will make him effective to the uttermost, and the enemy will tremble.
