What Is Sin? A Plain-Language Explanation

In the Bible, sin is turning away from God — failing to love Him and to love other people as we were made to. It includes wrong things we do, good things we fail to do, and the bent of the heart underneath both.

The most common New Testament word for sin means “to miss the mark.” Sin is not mainly about breaking arbitrary rules. It is about a broken relationship with the God who made us.

More than bad behaviour

Jesus said the greatest commandments are to love God with all your heart, soul, mind and strength, and to love your neighbour as yourself. Sin is everything that falls short of that — which means it reaches further than the obvious headline wrongs.

It shows up in what we do: lying, cruelty, greed. In what we leave undone: James says if anyone knows the good they ought to do and does not do it, it is sin. And in what we want: Jesus taught that anger and lust begin in the heart.

Where it comes from

Genesis tells of the first humans choosing to trust themselves rather than God. Christians understand that choice as the root of a condition every person now shares: a pull away from God that we are born with and then confirm by our own choices. Paul puts it bluntly: “All have sinned and fall short of the glory of God.”

That is a leveller. It means no one can look down on anyone else.

Why it matters

Sin damages everything it touches: our relationships, our own hearts, the world. Most seriously, it separates us from God, who is perfectly good. The Bible says the wages of sin is death — not only physical death but life cut off from its source.

We cannot fix this by trying harder, any more than someone can pull themselves out of a pit by their own hair.

What God has done about it

This is where the bad news becomes good news. The same verse continues: “but the gift of God is eternal life in Christ Jesus our Lord.” Jesus lived without sin and died on the cross bearing ours. Paul writes that God made Him who had no sin to be sin for us, so that in Him we might become the righteousness of God.

Forgiveness is offered to everyone, however far they have gone. John writes that if we confess our sins, God is faithful and just and will forgive us.

Do Christians still sin?

Yes. Christians are forgiven, not finished. But something has changed: sin is no longer in charge, God's Spirit is at work in them, and when they fail they come back to God honestly rather than hiding.