In Christianity, sin is an immoral act and transgression of divine law. The doctrine of sin is central to the Christian faith, since its basic message is about redemption in Christ.

The term hamartia derives from the Greek ἁμαρτία, from ἁμαρτάνειν hamartánein, which means "to miss the mark" or "to err". It is most often associated with Greek tragedy, although it is also used in Christian theology. The term is often said to depict the flaws or defects of a character and portraying these as the reason of a potential downfall. However, other critics point to the term's derivation and say that it refers only to a tragic but random accident or mistake, with devastating consequences but with no judgment implied as to the character.