1 John 3:1-10 NIV
See what great love the Father has lavished on us, that we should be called children of God! And that is what we are! The reason the world does not know us is that it did not know him. Dear friends, now we are children of God, and what we will be has not yet been made known. But we know that when Christ appears, we shall be like him, for we shall see him as he is. All who have this hope in him purify themselves, just as he is pure.
Everyone who sins breaks the law; in fact, sin is lawlessness. But you know that he appeared so that he might take away our sins. And in him is no sin. No one who lives in him keeps on sinning. No one who continues to sin has either seen him or known him.
Dear children, do not let anyone lead you astray. The one who does what is right is righteous, just as he is righteous. The one who does what is sinful is of the devil, because the devil has been sinning from the beginning. The reason the Son of God appeared was to destroy the devil’s work. No one who is born of God will continue to sin, because God’s seed remains in them; they cannot go on sinning, because they have been born of God. This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not God’s child, nor is anyone who does not love their brother and sister.
NIV: New International Version