John emphatically reminds us that he’s an eye witness who lives, eats and breathes with Jesus. In this letter, he’s quite short in his declarations, as there’s no room for our negotiating the truth of his testimony. He’s quite clear in declaring that, in God, there is no darkness at all. John uses this phrase to sharply confront those of us who claim to be believers in God, and in the Son He sent, yet continue to walk in darkness. In this case, we’re nothing more than liars before God and to ourselves.
Yet, in this rather terse tone, we find encouragement. He reminds us that we need not fear being bound to walking in darkness any longer. God is light and Jesus always walks in that light. Therefore, if we walk in the light as He is in the light, we (God and man) have fellowship with one another and the blood of Jesus, His Son, purifies us from all sin (v7). Furthermore, we’re blessed with the continued promise that, if we do sin, Jesus made the atoning sacrifice for sin, and He’s always at the right hand of the Father as our advocate
When we confess our sin, admitting our guilt, without trying to excuse, minimize or deny it, we still have every confidence that Jesus has already atoned for that sin. When we, in proper humility, repent, to approach God with a pure and contrite heart, we’re restored – in right and ability – to walk out of our darkness and into His light. Walking in the light doesn’t mean we’re guaranteed to live out our lives perfectly. It means that we’re so close to Jesus in our relationship that we continue to walk in His righteousness before our God.
If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness. 1 John 1:9
