A sermon on Matthew 5:13-20 by Nathan Nettleton
A video recording of the whole liturgy, including this sermon, is available here.
Acknowledgement: This sermon builds on a much shorter one from 1999, and the new material, almost half the sermon, draws heavily on this recent article by my dear friend Jarrod McKenna.
“You are the salt of the earth,” says Jesus.
It’s not a command: “Be the salt of the earth,” or even a suggestion: “It would be good if you could be the salt of the earth.” Jesus simply states it as a fact. “You are the salt of the earth.” He goes on to say that we can be good salt or bad salt, but either way, we’re it. We, the people of God, are the salt of the earth. If we fail to have the effect that salt is meant to have, there is no plan B. We are the salt of the earth.
Likewise, Jesus says, “You are the light of the world.” Again, we’re it. If the light is put under a bucket, it’s wasted – burning fuel for no benefit – but it is still the only light there is. We are the light of the world.
When Jesus calls his followers salt and light, he is not offering comforting poetry for private devotion. He is naming a public responsibility. Salt preserves what would otherwise decay. Light exposes what prefers to remain hidden. These are not gentle images. They are practical, earthy, and at times uncomfortable. Salt stings when it touches a wound. Light can feel harsh when it reveals truths we would rather not see. Jesus is not describing a faith that stays safely away in our inner world. He is describing a faith that has real-world consequences.
These sayings in the Sermon on the Mount form the bridge between the Beatitudes – Jesus’s illustrations of the kind of characteristics God really values in people – and his discussion of the law of Israel, the beginning of which we heard read. “Do not think I have come to abolish the law, not to abolish but to fulfil.”
We often struggle with understanding a lot of this stuff because we mostly hear the different sections on different weeks, detached from one another, and so we take them in isolation. When we hear “not to abolish the law but to fulfil it” in isolation, Jesus can sound like a legalistic hardliner on a full-on law and order crusade, doubling down on rules and judgement. And then we wonder why we have trouble reconciling that Jesus with the one who heals on the Sabbath and eats with outcasts.
But if we hear them together by reading the Sermon on the Mount as a whole, the connections begin to come into view. Suddenly it then sounds more like, “You want to know how we go about fulfilling the law? Bless those who hunger and thirst for justice. Bless the peacemakers. Bless those who grieve the pain and brokenness of the world. Bless the poor, the meek, the merciful, the persecuted. That’s how the law is fulfilled. That’s what being salt for the earth looks like.”
“You are the salt of the earth.” Eugene Peterson translates it like this:
“Let me tell you why you are here. You’re here to be salt-seasoning that brings out the God-flavours of this earth. If you lose your saltiness, how will people taste Godliness? You’ve lost your usefulness and will end up in the garbage. Here’s another way to put it: You’re here to be light, bring out the God-colours in the world.”
God is present and active in the world all the time. But God acts through us. The whole world is full of the presence of God, but if no one’s dancing to God’s song, that presence goes largely unnoticed. Just as many people can barely taste the flavours of food without salt to draw them out, so too the godliness of life becomes difficult to discern unless it is embodied, unless it is lived out courageously, publicly, and imperfectly but boldly.
So what might it look like to be salt and light in the times we are living through?
Even without looking a few years ahead to the increasingly inevitable climate catastrophe, we are living in a world in desperate need of salt and light, right now. Here in Australia – a nation that likes to pride itself on being safe and peaceful – we have witnessed two racist terrorist attacks in less than two months.
The one at Bondi Beach in December got a lot more news coverage, and understandably so given the death toll. But the attempted bombing in Perth on January 26th could have killed just as many. It was aimed at Aboriginal people and those standing in solidarity with them at an Invasion Day rally, and had the fuse not failed, many who were there would not be alive today.
We are immensely grateful that it failed, but what followed for many was something else: silence. Days of silence. Silence from leaders. Silence from much of the media. And for those who were there, for those already carrying the weight of history, that silence was not neutral. It was overwhelming. It deepened fear, grief, and isolation. As one survivor said, that silence hurt more than anything else.
We know that the feeling of being under attack was felt by the whole Jewish community after Bondi, not just those who were there or who knew someone who was shot. So the fact that the Perth bomb failed to explode doesn’t change the the fear and anxiety caused by knowing what it was intended to do. It leaves a whole community feeling under threat.
James Baldwin once wrote, “Every bombed village is my hometown.” Do you hear that? That is what salt and light sound like in a violent world: a refusal to distance ourselves, a refusal to say, this has nothing to do with me. To be salt and light is not first of all to offer commentary, but to stand where the pain is and tell the truth about it.
In the wake of racist terror – acts designed to dehumanise, intimidate, and terrify – Jesus’s words refuse to let us retreat into neutrality. To be salt and light in this moment means telling the truth about racism in our society: not only as individual prejudice, but as a system of stories, habits, and fears that have been allowed to fester in the dark. It means resisting the temptation to spiritualise faith into something that offers private comfort while leaving public harm untouched.
Salt does not exist for itself. Light does not shine for its own sake. Jesus reminds us that salt and light exist for the world, not against it. Light does not shame; it shows the way home. Salt does not dominate; it quietly makes life possible. In a time of grief and anger, the followers of Jesus are called to be visibly aligned with those who are targeted, to practice solidarity that is costly and sustained, and to model a different way of being human together.
Our good works, Jesus says, are not about moral superiority. They are not about being seen as better people. They are about revealing the character of God – a God whose glory is glimpsed wherever dignity is restored, wherever fear is confronted, and wherever love refuses to be extinguished by hate.
Salt stings in open wounds. Light can be painful to eyes accustomed to darkness. But Jesus does not let us off the hook by offering a faith that is gentle but ineffective. If we are the salt of the earth, then sometimes our calling is to sting – not in order to harm, but to heal. To tell the truth about racism, about fear, about indifference, and about those who profit from them. To refuse the cheap piety of saying “at least it wasn’t worse” without also asking why it happened at all, and why some lives are treated as more grievable than others. None of this is likely be welcomed. But silence, too, is a choice – and often a choice whose costs fall most heavily on those already bearing the weight.
Biblical law alone – the written word, the rules on the page – cannot be salt for the earth. The word must take flesh in us. As Isaiah made so clear in our first reading, when people just go by the written word they end up with just another version of death. People can fast and offer the required prayers without living a word of it. Pedantic law-keeping is not life. God is not the least bit impressed with anyone’s religious observances if they continue to live without mercy, compassion or integrity. A prayer that is not lived is a prayer that is not heard.
And yet Jesus says, “I have not come to abolish the law, but to fulfil it.” We do not fulfil the law by listing the commandments and ticking them off religiously. We fulfil it as the mind of Jesus is formed in us, as gratitude for grace becomes a way of life, as compassion becomes a reflex rather than an exception.
By all means, read the scriptures. Meditate day and night on the law of the Lord, contemplate the God revealed therein. But don’t do it to memorise lists of do’s and don’ts to be frigidly executed and rigidly enforced. Do it so that the life of Jesus may be more deeply formed in you, and may bubble forth in courageous love, in joyous living, in full-flavoured passion for life, in all-embracing compassion for all who share the earth with you, and in a hunger and thirst for justice that refuses to be content while others are being left behind.
The truth is: hatred does not grow in a vacuum. It grows where fear is cultivated, where inequality deepens, where people are taught to blame the vulnerable while the powerful go unnamed, unless of course they are named in the Epstein files, but even then the system will shield them from real consequences.
Racism is not merely something people are “radicalised into online.” It is sustained by histories of land theft, by ongoing disparities in health, housing, incarceration, and life expectancy, by a society that too often treats First Nations suffering as background noise. To reject the normalising of this requires not less radicalism, but more – a radicalism rooted in love.
“You are the salt of the earth. You are the light of the world.” The purpose of our life together is to bring out the flavour, the colour, the zest – the godliness – of creation. Sometimes our saltiness will enrich what is already good. Sometimes it will help preserve what might otherwise be lost. And sometimes it will sting in the open wounds of the world – not to harm, but to heal.
If we do not mourn the hurts of the world, if we do not hunger and thirst for justice, if we do not strive for peace, how will anyone see beyond the greyness and hardness of a culture that has spent generations training us to look away? How will anyone glimpse the reign of God breaking in?
Aunty Lilla Watson, sharing the wisdom of her Murri People, once said, “If you have come here to help me, you are wasting your time. But if you have come because your liberation is bound up with mine, then let us work together.”
In this fragile moment, being salt and light means choosing courage over comfort, truth over denial, and a love strong enough to be seen. The word must take flesh in us. And in doing so, our righteousness will exceed that of the most meticulous nit-picking legalist – not because we have kept the rules better, but because love has been allowed to flood our lives and overflow into our world.
And in that – that living, breathing fulfilment of the law – God’s glory will be seen.
“You are the salt of the earth!”