As we discussed last time, the world is a corrupt and dark place. But in Matthew 5:13-16, Jesus explains that God has a plan for influencing the world with good.

You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled under foot by men.

You are the light of the world. A city set on a hill cannot be hidden; nor does anyone light a lamp and put it under a basket, but on the lampstand, and it gives light to all who are in the house. Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven.

God’s plan is to bring salt and light to the world through his disciples — through believers. So whose responsibility is this? It is ours.

The pronouns here in the Greek are emphatic. Jesus is saying, “You only are the light, you only are the salt, nobody else! You’re it, and if you do not retard the corruption, and if you do not bring the light to bear on the world, there will be no retardation and no light.”

We must live in the world, distinct from the world, if we are to fulfill the plan that Jesus set about to fulfill in the world. We cannot be corrupted by it; we cannot swallow its immorality. We cannot swallow its materialism. We cannot swallow its self-centeredness. We cannot swallow its easy solutions. We cannot listen to its philosophies.

A literal translation of verse 13 would read this way: “The only salt of the earth is you.” Here we are in the midst of a decadent and dark society, and the only salt of this place is you.

By the way, the “you” is plural. He’s talking about the collective body of believers. You don’t put one grain of salt on anything. You don’t say, “Pass the salt,” and then pick out one grain and drop it on there. It only functions in combination with other pieces of salt. And the church, to influence the world, must be collective salt. It’s not enough to be all alone at it. We’ve got to be at it together as a collective influence.

So believers are the salt of the earth. The verb here, este, stresses being. We are the salt, and we continue to be the salt, and we are the only salt in the world.

Let me add this: It’s not what we should be, it’s what we are. Like it or not, you are the salt of the earth. The only question is whether you’re salty or whether you’ve lost your flavor. The idea isn’t, “Please be salt.” It is, “You are salt.”

If you are a believer, you’re salt. If you’re a believer, you’re light. It’s not, “Well, I’m a new Christian and I certainly would like to become salt.” It’s not, “I’m growing toward being light.” No. You are light. You are salt. The question is whether you’ve got any taste and whether you’ve got any shine.

As believers, we’ve been totally separated from the world. Consider John’s words:

For whatever is born of God overcomes the world; and this is the victory that has overcome the world—our faith. Who is the one who overcomes the world, but he who believes that Jesus is the Son of God? (1 John 5:4-5)

When you believed in Christ, you overcame the world, you stepped out of the darkness of the world and into the light of the Son.

You may ask, “What do we mean by ‘light’?” It means the truth and the life of God revealed. We are no longer in the darkness; we are in the light, and we are the light of the world. Reflecting the light of the Son, we are moons, that the world may know the truth of God.

So we are salt to retard the corruption and we’re light to manifest the truth. By our influence, we retard corruption. By our words and lives, we manifest the truth. So you have here the influence of a silent testimony and the impact of a verbal and living testimony. Our salt influence may be silent and hidden, as salt is rubbed into meat to preserve it. But our light influence has to be open and ablaze in the way we live and in the manifestation of verbalizing the gospel of Jesus Christ.

Salt is unlike the medium in which it is placed. Light is unlike darkness. God has changed us from being part of the corrupting, stinking, foul meat of the world to be the salt that can preserve it, and from being in the gloomy mist of darkness to being light that can expose it.

Worldliness and secularization are totally condemned in this passage. You cannot be a part of the system. We can’t have people who claim to be Christians and never separate from the evil system; it can’t be done.

So, our Lord connects the great blessedness of the preceding Beatitudes with a responsibility. If God has graciously given us the kingdom of heaven, comfort, the earth, righteousness, mercy, access to Himself, sonship, and a great reward, He has also given us the responsibility to live as salt and light.

It’s a challenging responsibility. But it’s also vastly rewarding. And next time we will examine the nature of this responsibility more closely by looking at Jesus’ first metaphor, “You are the salt of the earth.”

This post is based on a sermon Dr. MacArthur preached in 1979, titled “You Are the Salt of the Earth.”