Luke 11:51

from the blood of Abel to the blood of Zachariah, who perished between the altar and the house. Yes, I tell you, it shall be required of this generation.

John 8:44

You are of your father the devil, and the desires of your father you will to do. He was a murderer from the beginning and stood not by the truth; for truth is not in him. When he speaks a lie, he speaks from his own; for he is a liar, and the father of him [that lies].

1 John 3:10

By this are the children of God manifest, and the children of the devil; no one that does not righteousness is of God, and no one that loves not his brother.

1 John 3:12

not as Cain was of the evil one and killed his brother; and why did he kill him? because his works were evil, and his brother's righteous.

1 John 3:15

Every one that hates his brother is a murderer; and we know that no murderer has eternal life continuing in him.

Treasury of Scripture Knowledge

Summary

And she again bare his brother Abel. And Abel was a keeper of sheep, but Cain was a tiller of the ground.

Bible References

A keeper

John 8:44
You are of your father the devil, and the desires of your father you will to do. He was a murderer from the beginning and stood not by the truth; for truth is not in him. When he speaks a lie, he speaks from his own; for he is a liar, and the father of him [that lies].
1 John 3:10
By this are the children of God manifest, and the children of the devil; no one that does not righteousness is of God, and no one that loves not his brother.