1 John 1
v.3
We proclaim to you what we have seen and heard, so that you also may have fellowship with us. And our fellowship is with the Father and with his Son, Jesus Christ.
v.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, his Son, purifies us from all sin.
We would have expected John to say, “We have fellowship with God.” That is true, but already in the idea of walking together with God in the light. John wants to make it clear that fellow Christians who walk in the light enjoy fellowship with each other. This leads to an important idea: if we do not have fellowship with one another, then one party or both parties are not walking in the light. Two Christians who are in right relationship with God will also naturally be in right relationship with each other.
We can be cleansed, by the blood of Jesus, from all sin. The sin we inherited from Adam, the sin we committed as kids, the sins of our growing up; sins against our father, against our mother, against our brother and sister; sins against our husbands or wives, against our children; sins against our employers or our employees, sins against our friends and our enemies; lying, stealing, cheating, adultery, swearing, drugs, booze, promiscuity, murder; sins that haunt us every day, sins we didn’t even know we did – all sin can be cleansed by the blood of Jesus.
The author is combating the heresy that boasts of knowledge of and communion with God but neglects fellowship with other Christians. True fellowship with God comes through other people; fellowship with them is the proof of fellowship with God.
It is not the experience of Christian brotherhood, but solid and certain faith in brotherhood that holds us together. That God has acted and wants to act upon us all, this we see in faith as God’s greatest gift, this makes us glad and happy, but it also makes us ready to forego all such experiences when God at times does not grant them. We are bound together by faith, not by experience.
See more in Maclaren on 1 John 1 7 1John1 v 7.
v.9
If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness.
Our sins are not forgiven because we confess… However, confession is still vital to maintain relationship with God, and this is the context John speaks from. As God convicts us of sin that is hindering our fellowship with Him, we must confess it and receive forgiveness and cleansing for our relationship with God to continue without hindrance.
v.10
If we claim we have not sinned, we make him out to be a liar and his word has no place in our lives.
“No man was ever kept out of God’s kingdom for his confessed badness; many are for their supposed goodness.” (Trapp)