Cain and Abel
The first child born to Adam and Eve was Cain. A little later they bore another son, Abel. Cain became a farmer, while Abel became a shepherd.
In the course of time, the two brought offerings to the Lord. Cain brought a sheaf of ripe, golden corn. Abel's present was a new born lamb chosen from his flock. God looked with favor on Abel's offering but disdained Cain's. Cain got furious, some might say understandably, not realizing that God didn't accept Cain's offering because, unlike Abel who came before God in true faith and dedication, Cain lacked a sincerely obedient faith and because his deeds were evil. God takes pleasure in our offerings only when we try to live a righteous life according to his will.
Then the LORD said to Cain, "Why are you angry? Why is your face downcast? If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it."
Cain couldn't accept the correction or accept God's warning, and in increased rage, he invited Abel out into the fields and while there, he attacked him and killed him.
Then the LORD said to Cain, "Where is your brother Abel?" "I don't know," he replied. "Am I my brother's keeper?"
The LORD said, "What have you done? Listen! Your brother's blood cries out to me from the ground. Now you are under a curse and driven from the ground, which opened its mouth to receive your brother's blood from your hand. When you work the ground, it will no longer yield its crops for you. You will be a restless wanderer on the earth."
Horrified that he would be killed without the protection of God, Cain cried to the Lord in fear. But God assured Cain that he would put his mark on him so that nobody would harm him. And with that, Cain, a pioneer of God-separated human civilization - went out from the Lord's presence and lived in the land of Nod, east of Eden.
Safe with the mark of God, Cain married. His wife became pregnant and gave birth to a son named Enoch. Meanwhile, God gave Adam and Eve another child, a son named Seth. And the world grew.