By Lindsey Smith, Indigenous Missionary Lead
I’ve probably listened to half a dozen sermons on Matthew 5:13-16, exploring what it means to be salt and light in a world stricken by the sickness and darkness of sin. Maybe you’re in the same boat, but the beautiful thing about God’s Word is that it can be simple enough for a child to understand, yet deep enough for even the most intellectual mind to keep learning and going deeper into the truths God has given.
I always enjoy learning about the culture and significance behind the phrases and examples in Scripture, especially when it comes to metaphors. Jesus, like many other Jewish teachers of His time—and even before His time, like King Solomon—used a method of teaching known as parallelism or paired metaphors. In doing so, He often presented two examples for each concept He wanted people to understand. Sometimes these examples were meant to contrast each other to make a point, and sometimes they built upon each other, so the second could add depth or a new layer of meaning to the first. We see this clearly in Jesus’ call to His disciples to be both the salt of the earth and the light of the world. In doing this, Jesus teaches that discipleship is meant to have both an internal and external effect on the believer and that our influence on this earth should be a quiet but potent presence as much as it is a visible demonstration of the Kingdom of God to those around us.
Salt: Hidden Influence
This familiar call to be salt in the world has some obvious connotations: believers are meant to preserve and bring flavor to a world that is decaying and has lost its savor. But salt was used for far more than culinary purposes in Jesus’ day. In ancient Judea, salt was incredibly valuable and an essential part of life. It was not uncommon for part of a Roman soldier’s paycheck to come in the form of salt (fun fact: that’s where we get the word salary and phrase “worth their salt”).
Salt was also used to treat wounds, applied to newborn babies, and exchanged when making covenants—as a symbol of faithfulness and the unchanging quality of the agreement. Jewish worshippers were instructed to offer salt with their sacrifices, symbolizing faithfulness and purity of heart (Leviticus 2:13). Salt also symbolized judgment and was used by conquering nations to salt the land of their enemies so it would no longer be fertile.
What I found most fascinating, though, was connected to Jesus’ words in the second part of verse 13: “But if salt loses its savor, it is good for nothing but to be tossed into the street and trampled underfoot.” I had always wondered how salt could lose its flavor—after all, it doesn’t go bad. I had even heard teachings that said this isn’t possible, and that Jesus’ point was: believers can’t help but influence the world for good. But anyone who has tried to follow Jesus without intention knows that’s not quite accurate. We don’t just drift toward faithfulness. Without purposeful pursuit of Christ, we naturally slide toward compromise, not impact.
What I found instead is that salt could lose its flavor when mixed with other minerals—like the kind of salt harvested from the Dead Sea. This kind of salt was much cheaper. Chemically, when sodium chloride (salt) is corrupted by other substances, it becomes less potent and useful and would often be used instead to salt roads and footpaths. In this way, throwing salt underfoot was a method of hardening the ground. What a sobering thought! When salt mixes with other minerals and is no longer sincere, its only strength is to harden. I can’t help but think of the other contrasting uses of salt—or make a further jump to the parable of the seeds and the sower, where the goal is to prepare our hearts as soft and fertile ground for God’s Word to take root. It makes me wonder if Jesus might’ve had that picture in mind when He described salt (disciples) that was no longer useful to the Kingdom because of a lack of inner sincerity.
Perhaps this points to the humbling reality that hypocrisy among believers can cause hardness of heart in those who witness it, making it more difficult for them to receive the truth God longs to plant. Whether or not Jesus was directly teaching this truth, or whether it’s just a nuance I found to be meaningful, it’s clear that He was calling disciples to a sincere, authentic life that would carry significant influence in the world around them.
Light: Illuminating What’s Hidden
Light holds deep metaphorical significance throughout Scripture. In fact, Jesus calls Himself the Light of the World in John 8:12. So for Him to also grant this title to His followers is both an honor and a privilege.
While salt has a permeating impact through subtle, direct contact, light transforms things on the visible spectrum. Light provides clarity and direction, revealing the right path. It’s meant to be seen, to draw the eye—and when an entire city of lights is gathered together, it becomes a corporate witness of life and safety.
Disciples of Christ are not called to settle only for internal integrity, though that’s an essential starting place. They’re also called to shine boldly for the Kingdom, pointing others to the true source of light and life: Jesus. Light pushes back darkness and draws the human eye toward its glory. Likewise, believers are to let their good works—flowing from sincere hearts of faith and purity before the Lord—shine out for all to see. Not so that they would be glorified, but so that others would glorify God with them.
So how do we live as light? It starts with walking in the Light ourselves, staying close to Jesus through His Word, prayer, and a community committed to truth. The more we behold Him, the more clearly we reflect Him.
Living as Both
The tension in this dual metaphor is that many of us are tempted either to give in to worldly influence and compromise (losing our saltiness), or to hide our light in fear (covering it with a basket). But Jesus calls us to wholehearted discipleship that is both pure and visible—discipleship that transforms our private, inner lives and overflows into our public, outer lives. We are not the source. Nor can our efforts achieve righteousness. But we can reflect what God has done in us by committing ourselves to His leading and submitting ourselves to the faithful teachings of our Good Shepherd.
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