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.

 Second, the man who claims that he abides in God ( 1 John 2:6) and in Jesus Christ must live the same kind of life as Jesus lived. That is to say, union with Christ necessarily involves imitation of Christ. 