To practice or not practice sin, that is, to live in or not live in sin, is not a matter of behavior but of whose children we are, the children of God or the children of the devil. Hence, it is a matter of life and nature. Men, as fallen descendants of Adam, are born children of the devil, the evil one (John 8:44), and possess his life, partake of his nature, and live in sin automatically and habitually. Practicing sin is their life. But the believers, who are redeemed from their fallen state and are reborn in their spirit, are the children of God, who possess His life, partake of His nature, and do not live in sin. Practicing righteousness is their life. Whether one is a child of God or a child of the devil is manifested by what he practices, righteousness or sin. A reborn believer may commit sin, and an unsaved man may do righteousness. Both are their outward behavior, not their outward living, and thus do not manifest what they are in their inward life and nature.