1 John 3:8-10

the one who practices sin is of the devil; for the devil has sinned from the beginning. The Son of God appeared for this purpose, to destroy the works of the devil. No one who is born of God practices sin, because His seed abides in him; and he cannot sin, because he is born of God. By this the children of God and the children of the devil are obvious: anyone who does not practice righteousness is not of God, nor the one who does not love his brother.