In the Book of Genesis (Bible, Old Testament), Cain is a son of Adam and Eve. He killed his brother Abel.
Cain and Abel both gave gifts to God. God liked Abel's gift more than Cain's. Cain became jealous of Abel. Later, Cain hit Abel in the head with a rock. Abel died. When God asked Cain where Abel was, Cain pretended he did not know. He said, "Am I my brother's keeper?"
God punished Cain by exile: He made Cain leave the place where he lived. He made Cain go away. He told Cain that if he tried to build a farm, the earth "would not yield up its strength." When Cain said he was afraid, God put a mark on him to protect him.
Cain went east and lived as a wanderer. Some scholars say that the story of Cain was told to explain why some humans build farms and stay in one place and others move from place to place.
