“See what kind of love the Father has given to us, that we should be called children of God, and so we are” (3:1). This is just an amazing thing, i.e., that we are called children of God. The Bible has much to say about the judgment that comes upon sinners but we as God’s children have the assurance of forgiveness and eternal life, assurance that is not given to all. That phrase “children of God” is thrown around so loosely these days. You know . . . “we’re all God's children,” “the universal brotherhood of man,” etc. But John’s readers (and we) are not only called children of God; John wants us to know that we are INDEED children of God.
And what does this mean? Well, consider the following. Our Father loves us with so great a love! We will be like him, in all his purity. Our sin has been taken away. We have been born of God. We love one another. Our hearts do not condemn us, and we have confidence before God. We keep his commandments and do what pleases him. We abide in God. Whatever we ask from God, he gives us. We have his Spirit within us. Now, that’s the way to live! As a child of God!
Not all the nobles of the earth,
Who boast the honors of their birth,
So high a dignity can claim,
As those who bear the Christian name.
To them the privilege is given
To be the sons and heirs of heaven;
Sons of the God who reigns on high,
And heirs of joy beyond the sky. --Samuel Stennett (18th century)