in the Old Testament, second son of Adam and Eve, who was slain by his older brother, Cain (Genesis 4:1–16). According to Genesis, Abel, a shepherd, offered the Lord the firstborn of his flock. The Lord respected Abel's sacrifice but did not respect that offered by Cain. In a jealous rage, Cain murdered Abel. Cain then became a fugitive because his brother's innocent blood put a curse on him.

The storyteller in Genesis assumes a world of conflicting values, and he makes the point that divine authority backs self-control and brotherhood but punishes jealousy and violence. Cain had not mastered sin (v. 7); he had let it master him. The narrator takes a somber look at the human condition, seeing a dangerous world of Cains and Abels. Nevertheless, God is on the side of the martyrs; he avenges their deaths in the ruin of the Cains. In the New Testament the blood of Abel is cited as an example of the vengeance of violated innocence (Matthew 23:35; Luke 11:51).