Behold, how great a love the Father has bestowed on us, that we should be called children of God! For this cause the world doesn't know us, because it didn't know him.
". . . the world hates the children of God (1 John 3:13), just as it hated Jesus (John 15:18 f.), since they do not belong to the world. This very fact is a further proof that the readers are children of God: the way in which the world does not recognize them as being on its side is proof that they belong to God." [Note: Marshall, p. 171.] 