3And by this we know that we have known him, if we keep his commandments. We have known him, if we keep his commandments... He speaks of that practical knowledge by love and affection, which can only be proved by our keeping his commandments; and without which we can not be said to know God as we should do.
4He who saith that he knoweth him and keepeth not his commandments is a liar: and the truth is not in him.
5But he that keepeth his word, in him in very deed the charity of God is perfected. And by this we know that we are in him.
6He that saith he abideth in him ought himself also to walk even as he walked.
7Dearly beloved, I write not a new commandment to you, but an old commandment which you had from the beginning. The old commandment is the word which you have heard.
8Again a new commandment I write unto you: which thing is true both in him and in you, because the darkness is passed and the true light now shineth. A new commandment... Viz., the commandment of love, which was first given in the old law; but was renewed and extended by Christ. See John 13.34.
9He that saith he is in the light and hateth his brother is in darkness even until now.
10He that loveth his brother abideth in the light: and there is no scandal in him.
11But he that hateth his brother is in darkness and walketh in darkness and knoweth not whither he goeth: because the darkness hath blinded his eyes.
Commentary
DoctrinalUnion with God is measured by obedient love, not by claims of insight. Christ’s advent discloses hearts by forcing a division: light for the nations and contradiction for the resistant.