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.
That we should be called the sons of God - That is, that we should “be” the sons of God - the word “called” being often used in the sense of “to be.” On the nature and privileges of adoption, see the Romans 8:15-17 notes; 2 Corinthians 6:18 note, and practical remarks on that chapter.