1 (My little children, I am writing these things to you so that you may not sin.) But if anyone does sin, we have an advocate with the Father, Jesus Christ the righteous One, 2 and he himself is the atoning sacrifice for our sins, and not only for our sins but also for the whole world.
3 Now by this we know that we have come to know God: if we keep his commandments. 4 The one who says “I have come to know God” and yet does not keep his commandments is a liar, and the truth is not in such a person. 5 But whoever obeys his word, truly in this person the love of God has been perfected. By this we know that we are in him. 6 The one who says he resides in God ought himself to walk just as Jesus walked.
7 Dear friends, I am not writing a new commandment to you, but an old commandment which you have had from the beginning. The old commandment is the word that you have already heard. 8 On the other hand, I am writing a new commandment to you which is true in him and in you, because the darkness is passing away and the true light is already shining. 9 The one who says he is in the light but still hates his fellow Christian is still in the darkness. 10 The one who loves his fellow Christian resides in the light, and there is no cause for stumbling in him. 11 But the one who hates his fellow Christian is in the darkness, walks in the darkness, and does not know where he is going, because the darkness has blinded his eyes. (NET)