John 13:31-35 New Revised Standard Version (NRSV)
The New Commandment
31 When he had gone out, Jesus said, “Now the Son of Man has been glorified, and God has been glorified in him. 32 If God has been glorified in him,[a] God will also glorify him in himself and will glorify him at once. 33 Little children, I am with you only a little longer. You will look for me; and as I said to the Jews so now I say to you, ‘Where I am going, you cannot come.’ 34 I give you a new commandment, that you love one another. Just as I have loved you, you also should love one another. 35 By this everyone will know that you are my disciples, if you have love for one another.”
1 John 1:5-2:11 New Revised Standard Version (NRSV)
God Is Light
5 This is the message we have heard from him and proclaim to you, that God is light and in him there is no darkness at all. 6 If we say that we have fellowship with him while we are walking in darkness, we lie and do not do what is true; 7 but if we walk in the light as he himself is in the light, we have fellowship with one another, and the blood of Jesus his Son cleanses us from all sin. 8 If we say that we have no sin, we deceive ourselves, and the truth is not in us. 9 If we confess our sins, he who is faithful and just will forgive us our sins and cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make him a liar, and his word is not in us.
Christ Our Advocate
2 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; 2 and he is the atoning sacrifice for our sins, and not for ours only but also for the sins of the whole world.
3 Now by this we may be sure that we know him, if we obey his commandments. 4 Whoever 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; 5 but 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: 6 whoever says, “I abide in him,” ought to walk just as he walked.
A New Commandment
7 Beloved, 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. 8 Yet I am writing you a new commandment that is true in him and in you, because[a] the darkness is passing away and the true light is already shining. 9 Whoever says, “I am in the light,” while hating a brother or sister,[b] is still in the darkness. 10 Whoever loves a brother or sister[c] lives in the light, and in such a person[d] there is no cause for stumbling. 11 But whoever hates another believer[e] is in the darkness, walks in the darkness, and does not know the way to go, because the darkness has brought on blindness.