Genesis 4:4-8

4Abel also brought some choice parts of the firstborn animals from his flock. The Lord approved of Abel and his offering,

5but he didn’t approve of Cain and his offering. So Cain became very angry and was disappointed.

6Then the Lord asked Cain, “Why are you angry, and why do you look disappointed?

7If you do well, won’t you be accepted? But if you don’t do well, sin is lying outside your door ready to attack. It wants to control you, but you must master it.”

8Cain talked to his brother Abel. Later, when they were in the fields, Cain attacked his brother Abel and killed him.