Matthew 5:13-16 - "Light and Salt"

Matthew 5:13-16

"Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men. Ye are the light of the world. A city that is set on an hill cannot be hid. Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house. Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven."

Our LORD, continuing His instruction to His disciples in the Sermon on the Mount, sets before them two vivid pictures that describe what it is to belong to His Kingdom. He does not call them to become something they are not, but declares what they already are by God’s Sovereign Grace. “Ye are the salt of the earth” (v.13). “Ye are the light of the world” (v.14). These words speak of identity, not effort.

When Christ says, “Ye are the salt of the earth” (v.13), He first teaches us that His disciples are precious. Salt in His day was not a trivial commodity. It was valued, traded, and even used as payment. This is where our language of worth and salary finds its roots. In the same way, the LORD’s people are precious—not because of anything in themselves, but because of what God has done for them. Their value is rooted in Grace, obtained by the redeeming work of Christ. They did not make themselves salt; they were made so by sovereign and electing Purpose in Christ.

Salt also has a preserving influence. In a world without refrigeration, salt restrained corruption. Our LORD places His people in this world for that very reason. Left to itself, the world runs headlong toward decay. Yet God has purposed to preserve a people and to place them among their neighbors, communities, and workplaces as witnesses of His Grace. This preserving influence does not come from moral superiority, but from the Presence of Grace by the Spirit of God in Christ. The testimony remains clear: the only difference between the LORD’s people and others is the Grace of God.

Salt also adds flavor. This speaks to how the LORD’s people live and speak in the world. Grace seasons their words and conduct. Scripture confirms this when it says, “Let your speech be alway with grace, seasoned with salt” (Colossians 4:6). Grace shapes how believers speak, how they conduct business, how they respond to others. Though sin remains and failures are real, God's Grace in each of His own teaches a different response than that of the world.

Our LORD issues a warning: “But if the salt have lost his savour, wherewith shall it be salted?” (v.13). This does not teach that God’s true people can lose salvation. Rather, it exposes false salt—imitation religion, man-made profession, that lacks true substance. Such salt may appear genuine for a time, but eventually its emptiness is revealed, and it is “good for nothing, but to be cast out, and to be trodden under foot of men” (v.13). False profession brings reproach, while true Grace endures because it is God-given and God-preserved.

Our LORD then turns to the second image: light. “Ye are the light of the world” (v.14). This light is not generated by man. It is not artificial or temporary. The true Light is Christ Himself, and those who belong to Him shine only because His Light has shone into their hearts. Scripture declares, “For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ” (2 Corinthians 4:6). Believers are called "light" only as reflections of Christ. Like the moon reflecting the sun, they possess no light of their own. Yet this reflected light cannot be hidden. “A city that is set on an hill cannot be hid” (v.14). The LORD places His people where they are seen, not to draw attention to themselves, but to bear witness to Him.

This is why Christ says, “Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven” (v.16). These good works are not works of merit, but the fruit of His Grace for us in Christ. They are God’s works displayed in His people. The goal is not admiration of the believer, but the glory of God.

Salt and light both speak of distinction. Who makes this difference? God alone in Christ. Grace alone. God has set His people apart in a decaying and dark world to preserve and illuminate. They are not removed from the world, but kept in it for His purpose and glory. As long as the LORD gives breath, His people remain where He has placed them, bearing witness to Christ and His finished work on the cross on their behalf.

May we rest in this truth: we are salt and light by Grace, not by effort. And may God be glorified in all that He has done!