Adam and Eve had two sons: Cain and Abel. These two sons brought offerings to God. Cain - a tiller of the ground - brought of the fruit of the ground; Abel - a keep of sheep - brought a lamb. The smoke rose from Abel's offering only. This means that God accepted Abel's offering and refused Cain's (2).

Then Cain killed Abel. “And the Lord said unto Cain, where is Abel thy brother? And he said, I know not: Am I my brother's keeper? and he said, what hast thou done? the voice of thy brother's blood crieth unto me from the ground. And now art thou cursed from the earth, which has opened her mouth to receive thy brother's blood from thy