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.

 2:1-2 My little children, I am writing these things to you that you may not sin. But, if anyone does sin, we have one who will plead our cause to the Father, Jesus Christ the righteous. For he is the propitiating sacrifice for our sins, and not for ours only but also for the whole world. 