There were two brothers, Cain and Abel, “And Abel was a keeper of sheep,
but Cain was a tiller of the ground.”(Genesis 4:2). Since they were children
of the first people on the earth, they had a very strong belief in God,
and pretty good communications with Him also. They also had to pay for
those conveniences. One of them was an offering to God of their harvest.
Both brothers brought offerings, but for some reason God the almighty liked Abel’s offering better than Cain’s. Since we are talking about the beginning of the world that started the first rivalry between brothers. Cain decided to take matters into his own hands and slew his brother. Since God was omnipresent and an omniscient, He noticed something was not as it should be, and thought to himself: “I created Adam, then Eve and they had two sons. I see one around, so where is the second one? I should ask Cain where did his brother go, since I haven’t built any flying saucers yet, haven’t I?” Did I tell you God was old even then, and temporary losses of memory were pretty common for his age, So God speaks to Cain and asks: “Where is Abel, thy brother?” (Genesis 4:9). Cain was guilty, but just like O. J., did not want to admit it. But in this case we are talking about God, not Judge Ito. Cain, trying to look innocent, says: “I know not: Am I my brother's keeper?”
God is no Judge Ito. He sees something is wrong here, so he conducts an investigation of his own. He does not like what He finds. So he says to Cain: “What hast thou done? The voice of thy brother's blood crieth unto me from the ground.” (Genesis 4:10). Then Cain says "Unto the LORD, My punishment is greater than I can bear.” (Genesis 4:13). Punishments those days were different, no death penalty no civil law suits. Imagine what O. J. would say.
Cain then recognizes that “Behold, thou hast driven me out this day from the face of the earth; and from thy face shall I be hid; and I shall be a fugitive and a vagabond in the earth; and it shall come to pass, that every one that findeth me shall slay me.” (Genesis 4:14). In plain English Cain was sent to some remote place, no directions to it. Started his family and became the predecessor of all Evil. So if you see a monster or troll or O.J. on the street you can know right away that he is a kin of Cain