Jesus—His Life and Message: The Sermon on the Mount

(You can read about the intent for and overview of this series in this introductory article.)

Salt and Light

Jesus opened the Sermon on the Mount with the Beatitudes, which provide an overview of how those who follow Him should live their faith. Throughout the rest of the Sermon, He expressed further and more detailed principles which build on the Beatitudes.

One of those principles, following right after the Beatitudes, is:

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.¹

Having expressed what His disciples are meant to be—those who are poor in spirit, mourn, are meek, hunger and thirst for righteousness, are pure in heart, are peacemakers, and suffer persecution for righteousness’ sake—Jesus went on to give two metaphors regarding the effectiveness of such disciples and the potential ineffectiveness of those who do not live His teachings.

He began with telling His disciples that metaphorically they are “the salt of the earth.” In the ancient world, salt was much more important than it is today. The Mosaic Law required that sacrifices made in the Temple contained salt, and Roman soldiers received a portion of their wages in salt. Salt was vital for both the flavoring and preservation of food,² and both of these uses are significant for the meaning of the metaphor. A small amount of salt added to food permeates the whole dish, making it taste so much better. The attributes spoken of in the Beatitudes and throughout the Sermon on the Mount radiate from a true follower of Jesus and influence others for the better. Thus they are like “salt,” flavoring everyone around them.

In the ancient world, salt was used to preserve food, mainly fish and meat, keeping them from becoming putrid and decaying. The influence of believers in the world can and should influence individuals and society in a manner that works to preserve good and godly values, and counter that which is ungodly according to Scripture. One author puts it this way:

What is good in society his followers keep wholesome. What is corrupt they oppose; they penetrate society for good.³

Christians are meant to be a positive spiritual and moral force in the world through their example of living Jesus’ teachings, doing what they can to emulate Him, and sharing the good news of salvation with others.

After making the statement that the disciples are the salt of the earth, Jesus went on to speak of disciples who do not live His teachings, who don’t take on the attributes that He had just spoken of in the Beatitudes.

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.

Bible commentators generally explain that pure salt (sodium chloride) will not lose its saltiness, However, salt in Jesus’ day generally wasn’t pure, since there were no refineries, and thus could be understood as losing its saltiness or taste in one of two ways. The first is that salt in Palestine generally came from the Dead Sea and was more powderlike than salt today, and it also contained a mixture of other minerals. Since salt was the most soluble part of the mixture, it could be washed out, since sodium chloride is water-soluble. So if it was exposed to condensation or rain water, it could be dissolved and removed; and when that happened, though it still looked like salt, the white powder that was left neither tasted like nor had the preserving properties of salt. It was good for nothing.

The second way the tasteless salt is explained is that salt by nature cannot be anything other than salt. So the only way it can lose its saltiness is if it becomes adulterated in some way. In such a case, it loses its effectiveness and is no longer useful for either adding flavor or preventing corruption in food, and is therefore cast out as useless.

With either explanation, the point is made that salt which doesn’t function as salt is useless and loses its value. Like tasteless salt, disciples who lack genuine commitment to function as disciples become ineffective.

Jesus then used another metaphor, pointing out that the disciple’s life is meant to light up the world around them; and that those disciples whose lives do not reveal the Father’s works are like lights which aren’t seen.⁴

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.

Jesus said:

I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.⁵

The world needs the light of Jesus, which is made visible to the world through His disciples. Disciples are to be visible, like a city on a hill—which can be clearly seen from far away in the day, and is seen at night due to its lights.

Jesus also spoke of a lamp that gives light within a house. A typical peasant house in Israel contained only one room, so one lamp would have lit up the entire house. A domestic lamp in Jesus’ day was a shallow bowl of oil with a wick. It was normally stationary, placed on a lampstand. Jesus points out that people put the lamp on the stand to light the whole house; they don’t put it under a basket where the light can’t be seen. A basket, translated in some Bible versions as a bowl, was a vessel which was used to measure grain and held about nine liters. It was made from either earthenware or reeds. Putting such a vessel over the lamp would completely hide the light, and after enough time would eventually put the light out altogether.

For the lamp to fulfill its purpose of giving light, it needs to be visible; so covering the light would be absurd, since it would work against the purpose of the lamp. Likewise, part of the purpose of a disciple is to shed light, and in order to do so, the believer needs to let his or her beliefs be seen. To be effective Christians, we are to live in a manner which allows others to see that we are Christian, to see how a life in alignment with Jesus’ teachings is lived. In the same way that a city set on a hill is clearly seen, and a lamp gives light to the whole house, we are to be light from God to those we interact with.

Let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.

Later in the Sermon on the Mount, Jesus instructs His disciples that they shouldn’t let others see when they do good works, which seems at first glance to be in conflict with what He says here. Let’s look more closely at what He says in the next chapter of Matthew:

Beware of practicing your righteousness before other people in order to be seen by them, for then you will have no reward from your Father who is in heaven. Thus, when you give to the needy, sound no trumpet before you, as the hypocrites do in the synagogues and in the streets, that they may be praised by others. Truly, I say to you, they have received their reward. But when you give to the needy, do not let your left hand know what your right hand is doing, so that your giving may be in secret. And your Father who sees in secret will reward you.⁶

These verses will be covered more in depth later in this series, but the difference between the instructions to “let others see your good works” and “do your good works in secret” has to do with one’s motives and reasons for what one does. This is seen in the difference between practicing your righteousness before other people in order to be seen by them… that they may be praised by others, and letting your light shine before others, so that they may see your good works and give glory to your Father. Letting your light shine so that people will see your good works and give God the glory is much different than doing it for the purpose of your own glory.

In living our faith, we are to do all we can to reflect God—being loving, merciful, and compassionate in our actions; helping others, giving to those in need, etc. Our goal, however, should be to do these things for God’s glory, not our own. Of course, it’s only natural for people who see or hear about our being involved with others in need to think well of us. But that shouldn’t be the reason we do it. Our purpose for helping others, for putting Jesus’ teaching into action, needs to be our commitment to love God and to love our neighbor as ourselves. It is part of who we are as Christians, as our purpose is to live in a way that glorifies God. Since we have become part of God’s family due to our belief in Jesus, we reflect His attributes because He is our Father. We are part of the kingdom of God and therefore exhibit the traits described in the Beatitudes and throughout the Sermon on the Mount.

Being a follower of Jesus and His teachings is meant to set us apart. As Jesus said, You are not of the world, but I chose you out of the world.⁷ The apostle Peter expressed it this way:

You are a chosen race, a royal priesthood, a holy nation, a people for his own possession, that you may proclaim the excellencies of him who called you out of darkness into his marvelous light. Once you were not a people, but now you are God's people.⁸ 

Being a Christian, having the Holy Spirit within us, doing our best to put the things Jesus taught into practice, makes us different.

One time you were darkness, but now you are light in the Lord. Walk as children of light (for the fruit of light is found in all that is good and right and true).⁹

Disciples of Jesus are the light of the world, and like a city set on a hill which can’t be hidden, like a lamp that gives light to all within the house, we are called to let the light that is within us shine in a manner that others can see, so that they will glorify God. This isn’t theoretical. As Christians, we are meant to reflect the light of God into our world in order to light the pathway to Him. It is part of the job description of a believer. We are to be living advertisements for Him, drawing people’s attention to the light that shines from within us—the Spirit of God.

The calling of Christians is to be the salt of the earth and the light of the world. To be effective and true to our calling, we must remain salty and keep our light from being covered; otherwise we become ineffective—salt that has lost its flavor, light which benefits no one. Our commitment as followers of Jesus is to live His teachings so that the light within us shines before others; so that they see our good works, our loving actions, how we conduct ourselves in God’s love, and take notice and see God’s reflection within us. The hope is that they will want to know what has made us the way we are, thus opening the door to tell them of God’s love for them, resulting in them entering a relationship with Him and further glorifying Him.

May each of us truly be the salt of the earth and the light of the world.

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Note

Unless otherwise indicated, all scriptures are from the Holy Bible, English Standard Version, copyright © 2001 by Crossway Bibles, a division of Good News Publishers. Used by permission. All rights reserved.

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