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.

 As John sees him, the man of the world is the man who judges everything by his appetites, the man who is the slave of lavish ostentation, the boastful braggart who tries to make himself out a far bigger man than he is. 