1My 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; 2and he is the atoning sacrifice for our sins, and not for ours only but also for the sins of the whole world.
3Now by this we may be sure that we know him, if we obey his commandments. 4Whoever says, “I have come to know him,” but does not obey his commandments, is a liar, and in such a person the truth does not exist; 5but whoever obeys his word, truly in this person the love of God has reached perfection. By this we may be sure that we are in him: 6whoever says, “I abide in him,” ought to walk just as he walked.
7Beloved, I am writing you no new commandment, but an old commandment that you have had from the beginning; the old commandment is the word that you have heard. 8Yet I am writing you a new commandment that is true in him and in you, because the darkness is passing away and the true light is already shining. 9Whoever says, “I am in the light,” while hating a brother or sister, is still in the darkness. 10Whoever loves a brother or sister lives in the light, and in such a person there is no cause for stumbling. 11But whoever hates another believer is in the darkness, walks in the darkness, and does not know the way to go, because the darkness has brought on blindness.