They went out from us, but they didn't 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.

 2:9-11 He who says that he is in the light, and who at the same time hates his brother, is still in the darkness. He who loves his brother abides in the light, and there is nothing in him which makes him stumble. He who hates his brother is in the darkness and he is walking in darkness, and he does not know where he is going, because the darkness has blinded his eyes. 