In Jewish, Christian, and Islamic tradition, Cain and Abel were sons of Adam and Eve, the ancestors of the human race. Cain killed his brother Abel, becoming the first murderer. The story of Cain and Abel is echoed in the mythologies of many cultures and suggests several symbolic interpretations.

The First Murder. According to the book of Genesis in the Bible, Cain and Abel were the first two sons born to Adam and Eve after their banishment from the Garden of Eden. Cain, the elder, became a farmer, while Abel became a shepherd. They offered sacrifices to Yahweh, or God. Cain brought fruit and grain; Abel brought lambs. When Yahweh accepted Abel's offerings but rejected those of Cain, Cain was hurt and angry. In a jealous rage, he killed his brother.

As punishment, Yahweh ordered Cain to go forth and become "a fugitive and a vagabond in the earth." Then he placed a sign, known as the mark of Cain, on the...