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.

 2:7-8 Beloved, it is not a new commandment which I am writing to you, but an old commandment which you had from the beginning, the old commandment is the word which you heard. Again, it is a new commandment which I am writing to you, a thing which is true in him and in you, because the darkness is passing away and the light is now shining. 