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.
John again used a three-fold structure at the beginning of this section of the text. He described three signs or marks: of the end (1 John 2:18-19), of the believer (1 John 2:20-23), and of living in the light (1 John 2:24-25). 1 John 2:26-27 recapitulate and develop the revelation in 1 John 2:18-25.