Why the Ten Commandments Matter

20 July

Deuteronomy 4:4-15

There's a scene in the 2010 film The Book of Eli that has stayed with me for years. Denzel Washington plays a blind man crossing a post-apocalyptic America, carrying the last Bible in the world. He's spent years memorising every word of it, because it's the last one, and it's too precious to lose. At one point he's captured, and a young woman finds him praying before a meal. She's never seen anyone pray. She doesn't even know what it is. He takes her hands and teaches her.

It's a small moment in a brutal film. To encounter prayer, and the God behind prayer, for the very first time. I've been a Christian long enough that prayer is just part of every day. I take it for granted more than I'd like to admit. That scene reminded me what it looks like when someone hasn't.

The twist is that the villain eventually gets the Bible. He thinks it's a tool for controlling people. He opens it, and it's in Braille. He can't read a word. Meanwhile Eli, dying from a gunshot wound, makes it to San Francisco and dictates the entire thing from memory to a waiting scribe. Every word.

Moses would have understood that instinct. In Deuteronomy 4, his great final sermon to the people of Israel, he says it three times in six verses: don't forget. Don't let these words fade from your heart. Teach them to your children, and their children after them.

Israel's Wisdom

Deuteronomy isn't a law code. It's a sermon about the law, Moses' last one, preached to a new generation standing on the edge of the promised land. The people who left Egypt have already died in the wilderness. These are their children. Moses, knowing his own death is close, is preaching what they need to carry forward.

His opening argument is striking. Verse six: observe these laws carefully, for this will show your wisdom and understanding to the nations. The surrounding peoples, watching Israel live by these ten words, will say “surely this is a wise and understanding people”.

Ten sentences. More wisdom than a library of philosophy. But here's what Moses is careful to say: this wisdom doesn't come from Israel themselves. It comes from their proximity to God. What other nation has a god as near to them as the Lord our God is whenever we pray to him? The nearness of God is what produces the wisdom. Israel's job isn't to be impressive, it's to reflect who God is to a watching world.

Every ancient law code was written to protect the interests of a king. Israel's is different. It's the shape of life that emerges when God draws close to his people. And the laws themselves are righteous — genuinely, obviously good. It's worth sitting with each one over the coming weeks and asking honestly: is this a bad law? I think you'll struggle to make the case. And if you want to see what the Ten Commandments look like when someone actually keeps them perfectly, that's Jesus. The righteous law become a righteous man.

Known by His Word, Not His Image

Verse twelve: the Lord spoke to you out of the fire. You heard the sound of words but saw no form — there was only a voice.

At Sinai, God showed up in fire, cloud, and deep darkness. He gave Israel nothing to look at. No shape, no image, nothing to carve or bow down to. Every other religion in the ancient world gave people something visible to worship. Israel's God gave them something to listen to.

This is not a minor point. God is known by his speech, not his appearance. Our whole life as Christians is built on hearing and trusting his word — not manufacturing a god we can imagine and keep at arm's length. That's why we read things in Scripture that unsettle us, that we don't immediately agree with. A God who only ever says things we're comfortable with isn't actually God — he's just a projection of our own preferences. Every generation of Christians has faced the pressure to soften, update, or quietly set aside the parts of Scripture that aren't currently fashionable. The call is always the same: listen, even when it's hard.

Don't Forget

This is where Moses gets almost urgent. Don't forget. Teach your children. Remember the day you stood before God. Three times in six verses, before he's even finished telling them what to remember.

Nobody formally rejects the Ten Commandments. That's not how it usually goes. What happens is more gradual. We let them fade. We stop thinking about them until we've quietly reconstructed our own comfortable version, a private moral code that's a bit more lenient, a bit more suited to how we actually want to live. Don't do anything too terrible. Be reasonably kind.

James describes it as looking in a mirror and then walking away and immediately forgetting what you look like. We see ourselves clearly in God's law — and then we choose not to keep looking. It's rarely in the quiet moments that we forget. It's usually when we're right in the middle of temptation, and we know exactly what the law says, and we walk away from it anyway. The more we do that, the dimmer it gets.

Moses was anxious about memory because he already knew Israel would forget. They did. That's the point.

The Law Exposes Our Need for a Saviour

Here's the hardest and most important thing about the Ten Commandments: they're impossible to keep. Not difficult. Impossible. Jesus makes that clear in the Sermon on the Mount. Never killed anyone? But have you hated someone in your heart? Never committed adultery? But have you ever lusted? The disciples heard this and asked: then who can be saved? Jesus said: what's impossible for people is possible for God.

That's not a flaw in the law. That's the whole point. The law is righteous. We are not. The gap between those two facts is exactly what the law is designed to expose, to strip away any illusion that we can earn our way to God, to show us clearly that we need a saviour.

And underneath all of this runs a grace that's easy to miss: God saved Israel from Egypt before he gave them a single commandment. He didn't say obey these laws and then I'll rescue you. He rescued them first, and then showed them how to live as his people. Grace always comes before law. We don't receive grace by obeying, we receive grace, and then the law shows us the shape of the new life we've been given.

That's where this series is heading. Not guilt. Not a checklist. But a clearer view of who God is, an honest look at who we are, and a deeper love for Jesus, the only one who kept every commandment perfectly, and who gives us his Spirit so we can grow in doing the same.

Moses warned his people not to forget. He preached knowing they would. And yet here we are — more than 3,000 years and 138-plus generations later — still reading his words. That's not an accident.

Don't forget.