Cain was the first son of Adam and Eve, as well as the brother of Abel. The two brothers offered sacrifices to God, but Abel's animal sacrifice was deemed acceptable, whereas Cain's offering of produce was not. This gave rise to Cain murdering his brother, Abel. We have acquired the statement that Cain made to God after He had challenged Cain regarding this conflict between the brothers, in which Cain said, "Am I my brother's keeper?" Due to his sin of murdering Abel, Cain was marked by God and became a vagabond in the earth. When Cain responded to God's punishment of banishment, he responded that this was too great a punishment and that he would be killed by others. In response, God marked him and said that anyone who killed Cain would receive sevenfold the punishment should they do so. The Bible indicates that he traveled in his exile to the land of Nod, which is east of the Garden of Eden.
Genesis 4.1-17, 24, 25; Hebrews 11.4; 1 John 3.12; Jude 11