Cain and Abel are the first two sons of Adam and Eve. Out of jealousy and anger, Cain lures Abel into the field and kills him. When God confronts Cain, he denies responsibility, asking, "Am I my brother's keeper?" As punishment, God curses Cain to be a restless wanderer but also places a mark on him to protect him from being killed. The story highlights themes of jealousy, responsibility, and divine justice.