According to John sin is a practice which violates God's law, and such necessitates the forgiveness of God. This practice is caused by a state of pollution which necessitates cleansing. In the light of this Epistle we may properly speak of the twofold nature of sin and the twofold remedy. John makes a definite distinction between the children of God and the children of the devil. The verb xstiu indicates a state of existence, a mode of behavior, amanner of life.
People are on one side or the other.
The Church is identified with God, and the world is controlled by the evil one. The absence or presence of sin makes the difference. Men define sin differently, and this causes a real problem. If sin is defined in the absolute sense, complete freedom from sinning is impossible. The best Christian is liable to sin in terms of such a definition.