31 Behold, what manner of love the Father hath bestowed upon us, that we should be called the sons of God: therefore the world knoweth us not, because it knew him not.
English Standard Version
31 See what kind of love the Father has given to us, that we should be called children of God; and so we are. The reason why the world does not know us is that it did not know him.
31 What marvelous love the Father has extended to us! Just look at it - we're called children of God! That's who we really are. But that's also why the world doesn't recognize us or take us seriously, because it has no idea who he is or what he's up to.
New King James Version
31 Behold what manner of love the Father has bestowed on us, that we should be called children of God! Therefore the world does not know us, because it did not know Him.
New Living Translation
31 See how very much our Father loves us, for he calls us his children, and that is what we are! But the people who belong to this world don't recognize that we are God's children because they don't know him.
Little does the world know of the happiness of the real followers of Christ. Little does the world think that these poor, humble, despised ones, are favourites of God, and will dwell in heaven. Let the followers of Christ be content with hard fare here, since they are in a land of strangers, where their Lord was so badly treated before them. The sons of God must walk by faith, and live by hope. They may well wait in faith, hope, and earnest desire, for the revelation of the Lord Jesus. The sons of God will be known, and be made manifest by likeness to their Head. They shall be transformed into the same image, by their view of him.