Little children, let no one lead you astray. He who does righteousness is righteous, even as he is righteous.

 John is not setting before us a terrifying perfectionism; but he is demanding a life which is ever on the watch against sin, a life in which sin is not the normal accepted way but the abnormal moment of defeat. John is not saying that the man who abides in God cannot sin; but he is saying that the man who abides in God cannot continue to be a deliberate sinner. 