John describes the person of Christ, in whom we have eternal life by a communion with God, 1-4; to which we must add holiness of life to testify the truth of our communion and profession of faith and also to assure us of the forgiveness of our sins by Christ's death, 5-10.
1 That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon and our hands have handled, concerning the word of life 2 (For the life was manifested, and we have seen it, and we testify and show to you that eternal life which was with the Father and was manifested to us), 3 That which we have seen and heard we declare to you so that you also may have fellowship with us. And truly our fellowship is with the Father and with his Son Jesus Christ. 4 And these things we write to you so that your joy may be full.
5 This then is the message which we have heard from him and declare to you, that God is light, and in him is no darkness at all. 6 If we say that we have fellowship with him and walk in darkness, we lie and do not speak the truth. 7 But if we walk in the light, as he is in the light, we have fellowship with one another, and the blood of Jesus Christ 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 is faithful and just to forgive our sins and to 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.
Matthew Henry Commentary - 1st John, Chapter 1[➚]
[v.5-10] - Reference, Matthew 5:16
[v.9] - Reference, Psalm 32:5.