We have been considering the character of the Christian in the Beatitudes. We now come to the effect that believers, who have this kind of character, will have on the world. “You are the salt of the earth; but if salt loses its flavor, how shall it be seasoned? It is then good for nothing but to be thrown out and trampled under foot by men. You are the light of the world. A city that is set on a hill cannot be hidden. Nor do they light a lamp and put it under a basket, but on a lampstand, and it gives light to all who are in the house. Let your light so shine before men, that they may see your good works and glorify your Father in heaven” (Matt. 5:13-16).
Christ is speaking to a pretty non-descript group of people here. A more unimportant collection of individuals can scarcely be imagined. And yet He says to them that “”You, you are the salt . . .” and “You, you are the light . . .” God, through the cross, has put to shame the wise men of this world (1 Cor. 1:27). These fishermen? The light of the world?
These words of Christ necessitate a certain view of the world. Without the presence of Christians (indwelt by the light of Christ), the world is rotten, and the world is in gross darkness. In the ancient world, salt was used as a preservative to keep meat from putrefying. We miss the force of this picture because we are accustomed to using (just a little) salt for seasoning. The first influence of Christians is to keep the world around from getting as rotten as it otherwise would. The is the negative role of the saints.
The positive role of the saints is seen in the image of light. Light reveals the darkness for what it is, and rebukes that darkness. And light provides a wonderful image of how this rebuke is effectively made — silently. Light is never shrill. And in the grace of God, by the grace of God, light shows the way out of darkness.
Jesus is speaking about the importance of our witness as Christians. Without that witness, Christians are worthless and ridiculous. He makes these points with the figures of salt and light.
As Spurgeon once put it, meat can be salted but salt cannot be salted. Salt that has lost its pungency is worthless, and is trampled by men. And is this not the condition of the church today? Salt without saltiness is worthless.
Then there is the image of light. The picture Jesus gives is a comic one. Why would someone light a lamp, and then put it under a basket? Given the behavior, there is no reason to light it in the first place. A lamp under a bushel is ridiculous.
Jesus teaches that we must not be withdrawn and shy about our allegiance to Him. It is in the very nature of the Christian faith to have an influence on the surrounding culture. But the motive force for change is found in something the world does not have at all — salt and light. But we cannot put on airs — when they see our good works, they will glorify the Father. The world will know where this potency originated.
And few things are sadder than a person who has a covenantal connection to Christ, but does not have the root of the matter within him. As Martyn Lloyd-Jones put it, “The formal Christian is a man who knows enough about Christianity to spoil the world for him . . . He has enough “Christianity” to spoil everything else, but not enough to give him real happiness, peace and joy and abundance of life. I think such people are the most pathetic people in the world. Our Lord certainly says they are the most useless people in the world. They do not function as worldings or as Christians. They are nothing, neither salt nor light, neither one thing nor the other.”