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.

 2:15-17 Do not love the world nor the things in the world. If anyone loves the world, the love of the Father is not in him. For everything that is in the world--the flesh's desire, the eye's desire, life's empty pride--does not come from the Father but comes from the world. And the world is passing away, and so is its desire; but he who does God's will abides for ever. 