What is sin, and why does it matter so much?

Sin is the most unpopular word in the Christian vocabulary and the one without which none of the rest makes sense. Grace is not good news to someone who does not believe there is a problem. Nobody is grateful for a cure they were not sick enough to need.

What the word actually means

The main New Testament word is hamartia — an archery term. It means to miss the mark: to shoot at a target and fall short.

That image reframes everything. Sin is not primarily a list of forbidden actions. It is failing to be what you were made to be. The target is the life God designed for a human being — full-hearted love of God and neighbour — and the accusation is not that we occasionally step over a line but that we are consistently off-centre.

Other biblical words fill the picture out. Pesha is rebellion, deliberate breach of a relationship. Awon is crookedness, being twisted out of true. Adikia is injustice — sin as something done to other people, not merely against a rule.

It includes what you do not do

"Whoever knows the right thing to do and fails to do it, for him it is sin" (James 4:17).

This is where most self-assessment collapses. A person can go a whole day without lying, stealing or striking anyone, and still spend it entirely on themselves. Jesus' picture of final judgement in Matthew 25 turns on omissions: I was hungry and you gave me nothing, thirsty and you gave me nothing. Nobody in that scene is accused of an atrocity. They are accused of not noticing.

It is a condition, not only a tally

"Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned" (Romans 5:12).

The Bible does not describe neutral people who occasionally sin. It describes people with a bent, who sin because of what they are. This is what theologians call original sin — not the idea that we are as bad as we could be, but that no part of us is untouched, including our reasoning and our motives.

The evidence is ordinary and available. Nobody teaches a child to lie or to grab. We teach them not to. Every parent knows this, and every honest adult recognises the same machinery still running in themselves, better disguised.

What it costs

"Your iniquities have made a separation between you and your God, and your sins have hidden his face from you" (Isaiah 59:2).

The cost is not primarily punishment. It is separation — the severing of the relationship the whole of human life is organised around. Everything else follows from that: the ache of meaninglessness, the sense of being unable to be fully known and fully accepted at once, the compulsions and the fear of death.

"The wages of sin is death" (Romans 6:23). Paul chooses a commercial word. Wages are earned. They are what the work pays.

Look at Genesis 3, and notice how little the first sin looks like villainy. A doubt: "did God actually say?" A reinterpretation: God is holding out on you. A conclusion: I am better placed to determine good and evil than he is. Then hiding, then blame — Adam blames Eve and God ("the woman whom you gave to be with me"), Eve blames the serpent. The pattern is depressingly recognisable. Sin, then concealment, then the transfer of responsibility.

Why the diagnosis has to come first

This is why evangelism that begins with "God has a wonderful plan for your life" so often fails to land: it answers a question the person has not asked.

Paul spends the first two and a half chapters of Romans building the case for universal guilt before he mentions the remedy. The whole world is "held accountable to God" (Romans 3:19) — and only then, "but now the righteousness of God has been manifested apart from the law" (Romans 3:21). The but now only carries weight because of what precedes it.

Charles Spurgeon put the pastoral point sharply: nobody will ever value a physician until they know they are ill.

What to do with it

The response Scripture asks for is not despair and not self-improvement. It is confession and repentance.

"If we say we have no sin, we deceive ourselves, and the truth is not in us. If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness" (1 John 1:8-9).

Notice just. Not merely merciful — just. God can forgive without pretending, because the penalty was carried at the cross. This is why Christian confession is not grovelling. You are not talking your way back into favour; you are agreeing with God about something he has already dealt with.

Repentance is the turn that follows: metanoia, a change of mind that changes direction. Not perfect performance from here on — that is not on offer — but a genuine reversal of who is in charge.

The gospel is this: We are more sinful and flawed in ourselves than we ever dared believe, yet at the very same time we are more loved and accepted in Jesus Christ than we ever dared hope.— Timothy Keller

Both halves, held together. Either one alone will destroy you: the first without the second is despair, and the second without the first is sentimentality.