And this is the message we have heard from Him and announce to you: God is light, and in Him there is no darkness at all.
John proclaims that God is light and that no darkness exists in Him at all.
This verse opens the section by stating the theological truth that governs all claims to fellowship.
5And this is the message we have heard from Him and announce to you: God is light, and in Him there is no darkness at all. 6If we say we have fellowship with Him yet walk in the darkness, we lie and do not practice the truth. 7But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus His Son cleanses us from all sin. 8If we say we have no sin, we deceive ourselves, and the truth is not in us. 9If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10If we say we have not sinned, we make Him out to be a liar, and His word is not in us.