1 John 2:3-11

3And by this we do know that we know him, if we keep his commandments. 4He that saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him. 5But whoever keepeth his word, in him verily is the love of God perfected: by this we know that we are in him. 6He that saith he abideth in him ought himself also so to walk, even as he walked.

7Brethren, I write no new commandment to you, but an old commandment which ye had from the beginning. The old commandment is the word which ye have heard from the beginning. 8Again, a new commandment I write to you, which thing is true in him and in you: because the darkness is past, and the true light now shineth. 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 cause for stumbling in him.1 11But he that hateth his brother is in darkness, and walketh in darkness, and knoweth not where he goeth, because that darkness hath blinded his eyes.