They went out from us, but they did not belong to us; for if they had belonged to us, they would have continued with us. But they left, that they might be revealed that none of them belong to us.

Behold, how great a love the Father has bestowed on us, that we should be called children of God; and such we are. For this cause the world does not know us, because it did not know him.

unlike Cain, who was of the evil one, and killed his brother. Why did he kill him? Because his works were evil, and his brother's righteous.