World Wide Study Bible
a Bible passage
6 Whosoever sinneth hath not seen him. According to his usual manner he added the opposite clause, that we may know that faith in Christ and knowledge of him are vainly pretended, except there be newness of life. For Christ is never dormant where he reigns, but the Spirit renders effectual his power. And it may be rightly said of him, that he puts sin to flight, not otherwise than as the sun drives away darkness by its own brightness. But we are again taught in this place how strong and efficacious is the knowledge of Christ; for it transforms us into his image. So by seeing and knowing we are to understand no other thing than faith.