Prologue: Our Declaration
1What was from the beginning,1:1 Jn 1:1; 1Jn 2:13–14 what we have heard, what we have seen with our eyes, what we have observed and have touched with our hands, concerning the word1:1 Ps 119:25; Jn 1:1,4; 5:24; Php 2:16 of life — 
2that life was revealed,1:2 Jn 1:31; 21:1,14; Col 3:4; 1Pt 5:4; 1Jn 2:28; 3:5,8 and we have seen it and we testify and declare to you the eternal life that was with the Father and was revealed to us1:2 1Jn 5:20 — 
3what we have seen and heard we also declare to you, so that you may also have fellowship1:3 Php 3:10 with us; and indeed our fellowship is with the Father1:3 Mt 11:27 and with his Son, Jesus Christ.
4We are writing these things1:4 Other mss add to you so that our1:4 Other mss read your joy1:4 2Co 2:3; Php 1:4,25; 2:18 may be complete.
Fellowship with God
5This is the message we have heard from him and declare to you: God is light,1:5 Ps 27:1; 36:9; Jn 12:46; 1Tm 6:16 and there is absolutely no darkness in him.1:5 1Jn 2:5
6If we say, “We have fellowship1:6 2Co 8:4 with him,” and yet we walk in darkness,1:6 Pr 2:13; Is 9:2; 50:10; Jn 8:12; 12:35; 1Jn 2:11 we are lying and are not practicing the truth.1:6 Jn 14:6; 2Co 11:10; 3Jn 3
7If we walk in the light1:7 Eph 5:8–14; Php 2:15; Col 1:12–14; 1Th 5:5 as he himself is in the light, we have fellowship with one another, and the blood of Jesus1:7 Heb 10:19; 12:24; 1Pt 1:2,19; Rv 1:5 his Son cleanses us from all sin.
8If we say, “We have no sin,”1:8 Pr 20:9; Jr 2:35; Rm 3:9–23; Jms 3:2 we are deceiving ourselves, and the truth is not in us.
9If we confess our sins, he is faithful and righteous to forgive1:9 Ps 103:3; Jr 31:34; Mt 9:6; 26:28; Col 1:14; Jms 5:15 us our sins and to cleanse us from all unrighteousness.
10If we say, “We have not sinned,” we make him a liar, and his word1:10 Lk 8:21; Heb 4:12 is not in us.1:10 Jn 8:37