not as Qayin who was of the wicked one and killed his brother. And why did he kill him? Because his works were wicked but those of his brother were righteous.
In this the children of Elohim and the children of the devil are manifest: Everyone not doing righteousness is not of Elohim, neither the one not loving his brother.
“You are of your father the devil, and the desires of your father you wish to do. He was a murderer from the beginning, and has not stood in the truth, because there is no truth in him. When he speaks the lie, he speaks of his own, for he is a liar and the father of it.