What is sin?

Short answer

Sin is anything in thought, word or deed that falls short of God's holiness: breaking His law, living our own way instead of His, or failing to do the good we know. The Bible says all have sinned, and that God offers forgiveness in Christ.

Few words in the Bible are used as often, and understood as poorly, as sin. Many people hear it as a list of forbidden pleasures or as a religious word for feeling guilty. The Bible describes something deeper: a break in the relationship between people and the God who made them.

Its main answers fit into one short verse, and the rest of Scripture fills them out.

Sin is rebellion against God’s law

Whosoever committeth sin transgresseth also the law: for sin is the transgression of the law.
1 John 3:4 · King James Version (1769)

The Jamieson, Fausset and Brown commentary notes that this is a definition of sin, and that the Greek word for sin means missing the mark: God’s will is the target we are meant to aim at. The same commentary offers a simple picture: the crookedness of a line shows up only when it is laid beside a straight ruler.

Matthew Henry takes the point further. Sin, he says, is the rejection of God’s law, and rejecting the law means rejecting the authority of the One who gave it, and so God Himself. William MacDonald says much the same in other words: the sinner insists on his own way and puts his will above God’s. John MacArthur adds that the word John uses means more than breaking a rule. It describes living as if there were no law at all, in open defiance.

So sin is not only a matter of wrong actions. It begins in the heart that says no to God, and the actions follow. Paul even pictures sin as a master who pays his servants wages, as we will see below.

Sin is also the good we leave undone

When we think of sin we usually think of things done. James adds another side.

Therefore to him that knoweth to do good, and doeth it not, to him it is sin.
Jas 4:17 · King James Version (1769)

Albert Barnes notes that the statement is general, though James probably had in mind the plans his readers were making without any thought of God. John Gill writes that leaving a known duty undone is a fault, just as doing a known wrong is. John Wesley adds that such knowledge does not lessen the guilt, but increases it.

Jesus said something similar: the servant who knew his master’s will and did not do it received the heavier judgment (Luke 12:47). Knowing what is right and putting it off is not neutral. It is one of the ordinary ways ordinary people sin.

Everyone has sinned

The Bible does not split people into the sinful and the respectable. Paul spends the first chapters of Romans showing that Jews and Gentiles alike stand guilty before God, and then sums it up.

For all have sinned, and come short of the glory of God;
Rom 3:23 · King James Version (1769)

Wesley comments that all have sinned in Adam and in their own persons, by a sinful nature and by sinful actions. MacDonald also separates the two: people are sinners by birth and sinners by what they do. This is what Paul has in mind when he says that sin entered the world through one man, and death through sin (Romans 5:12). David’s confession that he was sinful from the time his mother conceived him points in the same direction (Psalm 51:5).

Christians explain differently how exactly Adam’s sin touches everyone else. Barnes remarks that Romans 5:12–21 has often been counted the hardest passage in the New Testament. But the main point is plain in the text itself: no one has reached God’s standard, and no one can reach it by their own effort.

The wages and the gift

The Bible is just as clear about where sin leads.

For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord.
Rom 6:23 · King James Version (1769)

Barnes explains that “wages” means what a person earns, what sin deserves. Adam Clarke adds the contrast that makes the verse so good to read: “A man may Merit hell, but he cannot Merit heaven.” What sin earns is paid out. What God gives in Christ is a gift.

Here the Bible’s answer to sin begins. God did not leave us at the point of the diagnosis. Christ died for us while we were still sinners (Romans 5:8), and the one who confesses his sins finds God faithful and just to forgive them (1 John 1:9).

If this question is close to you because of your own conscience, the next steps are in What is repentance? and How can I be saved?.