Commentary on Matthew 5:13-20
At this point, Jesus’ Sermon on the Mount turns to quotidian imagery.
Salt. Cities. Light. These everyday realities become the ground for an important and potentially challenging theological conviction: righteousness before God is bound up in the call of the law and the prophets.
That is, Jesus is not inventing the shape of such righteousness but tapping into an ancient vein of divine revelation.
First, Jesus evokes the utility of salt but also the limits of its usefulness. Salt that has lost its salty essence is no longer salt. It is no longer fit for its previous uses so it is tossed onto the path to be trod underfoot. This image strikes me as both evident but also a bit disquieting. After all, the Sermon on the Mount is not a reflection on cooking ingredients but on the shape of God’s high calling upon our lives. How is righteousness like salt exactly? And who or what exactly is that salt that has lost its saltiness?
Second, Jesus points to the utility of light, especially the way light spills over its surroundings. The lights of a city on a hill are a beacon to others. So, also a lamp is meant to light a room, not the diminished and truncated space under a bushel basket.
Jesus makes the connections between salt and light and righteousness explicit in verse 16. Jesus declares that we too ought to be light like that city on a hill, that uncovered lamp. We too ought to reflect the goodness of God so that others might see the shape of God’s goodness and thus be grateful to God. Notice that the light in this metaphor does not belong to us but is an overflow of God’s call and grace.
“Our good works” are not ours in that they do not belong to us for we are not the source of such good works; we are only the conduits of God’s righteousness, symbols pointing to a greater reality, signposts lighting the way to God’s righteousness, not our own. Yes, we may serve as “the light of the world,” but the conduit of glory for such light is not us or our achievements. That glory belongs to “your Father in heaven” (verse 16).
So also, Jesus calls us to be salt, to serve in the way we were designed to serve. But what if we do not? What if we lose our saltiness? What if we seek to occlude the light under a basket? The call of the Sermon of the Mount is high and costly and risky. The darkening of the light, the loss of the salt’s saltiness is not without consequence.
After all, Jesus makes clear that he is not obviating or making moot the law and the prophets. He stands in the streams of righteous hope and transformative justice that both have reflected God for generations of faithful Israelites. To abolish the law and the prophets is to declare that God’s voice has changed or, worse, that God’s voice was not to be trusted in the first place.
If we proclaim the Sermon on the Mount as a wholesale innovation rather than an outgrowth of ancient traditions of faith, we may find ourselves participating in abolishment of the law and the prophets. Indeed, Jesus wants to make clear that his teachings are not erasing a letter or even a stroke of the letter of the law. For Matthew’s Jesus, the Sermon on the Mount does not replace the law and the prophets but echoes them.
After all, when Jesus here refers to the law and the prophets, he is pointing to the trustworthy promises of God, to the affirmation at the head of the Ten Commandments that the God of Israel is a God who heeds the call of the enslaved and sets them free. Why would Jesus mute such a trustworthy and transformative promise? Why would our preaching seek to do the same despite Jesus’ clear teaching?
Perhaps we have too often done this in our preaching because we have neglected the shape of the law as promise and narrative and commandment. The promises God made, the actions God takes, the commands God voices are bound up together. And so, Jesus continues to explain in verse 19 that a rank of sorts in the kingdom of heaven depends on whether we live and teach the commandments or whether we reject and teach others to reject the commandments.
Again, this is not a call to mere moralism but a call to a life of trust in God. If we trust God’s promises, if we stand grateful for God’s actions, then we will bend our lives toward the life-giving ways God has called us to follow. Breaking a commandment is not just breaking a rule; it is denying the promises and actions of God. Teaching others to do the same is not just leading them astray but de-forming their very being as children of a God who promises and liberates and teaches us how to live towards abundant life.
The stakes are high, Matthew’s Jesus reiterates, as we close our passage. Verse 20 uplifts the righteousness of the scribes and Pharisees and asks those hoping to “enter the kingdom of heaven” to exceed it. Here, the scribes and Pharisees are less a foil for Jesus in his teaching than exemplars of the fulfilling of the law.
Jesus, however, has one more surprise to share in next week’s lectionary reading. As vital as the law’s commandments are, they may not ask enough of us. God authored those commandments, not as a barrier around obedience or as a limit to our faithfulness, but as a starting point for righteousness, an opening into a life attuned to God’s grace-filled will.