Salt and Light: Living the Gospel Changes the World

Continuing through the Sermon on the Mount, we come to possibly the most preached-on section: being Salt and Light. This has to do with the effect believers can have on the world around them when they live well.

Coming out of the Beatitudes, Jesus gets into it. He says, “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)

Who is Salt and Light?

To understand what it means to be salt and light, we must first understand who Jesus spoke to. In the last beatitude, he switched from third person descriptions of character qualities to a direct expectation of his listeners. Speaking to his disciples, he said, “Blessed are those who are persecuted for righteousness’ sake, for theirs is the kingdom of heaven. Blessed are you when others revile you and persecute you and utter all kinds of evil against you falsely on my account. Rejoice and be glad, for your reward is great in heaven, for so they persecuted the prophets who were before you” (Matthew 5:10-12, emphasis added).

Salt of the Earth

After telling his followers that they will be happy to be persecuted, he said to them, “You are the salt of the earth.” He connects these twin metaphors of salt and light to the character qualities formerly expressed in the Beatitudes. We can think of them as extensions of the same thoughts put forth in the Beatitudes.

So he says that salt “losing its saltiness” renders it useless. It ceases to do its job. In the same way, a Christian who is not poor in spirit, meek, merciful, etc. ceases to fulfill their purpose. They are “no longer good for anything except to be thrown out and trampled under people’s feet” (Matthew 5:13).

Salt represents the role of God’s people, and saltiness is the degree to which we live up to that role. So what is that role?

Sacrifice

In the Old Testament, salt was part of the sacrificial system. Israel included it with both grain offerings (Leviticus 2:13) and burnt offerings (Ezekiel 43:24), and it was an ingredient in the incense for temple use (Exodus 30:35). Jesus highlights the sacrificial use of salt in Mark 9:49. Speaking of a future order in the life to come, he says that “every sacrifice will be salted with salt.”

We know that under the New Covenant, the old sacrificial system is done away with. Christ himself, who is our Lamb, Priest, and Temple all in one replaces it. However, now our expression of “temple worship” is laying down our lives. Paul commanded us to offer our bodies to God as a “living sacrifice” (Romans 12:1). In prison, he said he was being “poured out as a drink offering” upon his readers’ faith. He referred to that faith also as a sacrificial offering (Philippians 2:17). And he also called us the “aroma of Christ to God” (2 Corinthians 2:15) a reference to incense offerings.

So Paul understood this. Our faith, our bodies, our very existence, is to be an ever-offered sacrifice.

Preservation and Disinfectant

The Hebrew mind symbolically tied salt’s sacrificial use to its everyday use as a disinfectant and as a preservative. Similarly, those who live by the Beatitudes will inadvertently purify and maintain the moral fabric of society. They will redeem the social order.

The Apostle Paul instructs believers in Colossians 4:6 to “let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person.” In other words, the way we speak to each other and to the world around us must be full of grace and understanding, but it also must contain sprinkles of truth and righteousness in order that we are being that salt of the earth to the people around us. And Jesus says, “Have salt in yourselves, and be at peace with one another” (Mark 9:50).

Destruction

This one is a bit obscure, but follow me. In the book of Judges, a power-hungry man named Abimelech deceived and manipulated people to make himself king of Israel, before Israel even had kings. He fought against the city of Shechem, and Judges 9:45 says he “fought against the city all that day. He captured the city and killed the people who were in it, and he razed the city and sowed it with salt.” Sowing salt into the soil served one purpose: dehydrating and destroying both living crops and the potential to grow more. Doing this to a city ensured the starvation of its people, because the effect of salt in the ground was so damaging.

With this use in view, Scripture often present salt as a sign of God’s judgment. Deuteronomy 29 has the Lord warning Israel of the blessings of obedience and the curses of disobedience to his law. One result of disobedience is “the whole land burned out with brimstone and salt, nothing sown and nothing growing, where no plant can sprout” (verse 23, emphasis added).

The first half of Mark 9:49, quoted above, says, “Everyone will be salted with fire.” This follows a discourse about judgment in Gehenna, or hell. He speaks of eternal fire for those who have not cut off those things which cause us to sin. Here “salted with fire” implies destruction and judgment. As the salt of the earth we are not to personally destroy sinners, as that would contradict the very Beatitudes Jesus has just taught. Rather, our lives preach a sermon of warning to the world. We show them that they can choose to become that salt by the grace of God, or experience fire in the life to come.

Light of the World

Following salt, Jesus calls us light as well. He says, “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 5:14-16).

This illustration more obviously relates to our impact on the world around us, although with a slightly different nuance. Salt affect the world tangibly. Light affects it visibly. Salt is usually unseen doing its job, but light is clearly seen; that is the whole point of light.

Jesus is again expressing the role of those who follow him and live out the Beatitudes. Elsewhere, he speaks against those who flaunt their good deeds because they love recognition. So his point here is not that. He doesn’t want us to flaunt what we do to make it about ourselves. Rather, Jesus wants his people unashamedly righteous. We must not keep the God we serve and the kingdom we represent to ourselves. If they remain hidden from the world, then those lost in darkness will remain without hope. Jesus, the True Light of the world, came to save the world, and who are we to hide him from it?

How to be Salt and Light

We have touched on this throughout the post, but Jesus summarizes the way he expects us to live in the world in the Beatitudes. Beyond this, the whole of his teachings further expresses these values, and more specifically, the whole Sermon on the Mount, found in Matthew 5-7, lays the groundwork for the rest of his teachings in the Gospels. So if you want to be salt and light, if you want to lead others to glorify the Father, then pay close attention to the teachings of Christ. Become addicted to his words. Seek his presence, and beg him to transform you more into his image. He will, and others will take notice.