When a child of God sins (and he will sin, 1 John 1:6-10), Scripture teaches that he must confess his sin to the one he has sinned against, seeking forgiveness. The Greek word for “confess” (homolegeo) literally means “to speak the same thing,” with the idea being “to assent, agree with.” Every sin that we commit is against God (in violation of His revealed will to us), therefore, we must confess our sins to the One against whom we have sinned. When the sin is against God alone and He is the only one who knows about it, confession needs to be made only to Him.
It is often the case that when a child of God sins against God that he has also sinned against a fellow Christian, as well. If a Christian lies to, gossips about or harshly treats a fellow Christian, he has not only sinned against God, but he has also sinned against that fellow Christian. What responsibility does the offending child of God have when his sin involves others?
The “general rule” still applies—we must confess our sin to the one against whom we have sinned. First, this is God (cf. 2 Sam. 12:13); then, it is to any knowingly affected by the sin (cf. Luke 15:18-21). When a brother has sinned against another, there is a responsibility to “go and tell him his fault between you and him alone” (Matt. 18:15). A sin that involves only one other person (or just a few others) can be handled “between you and him alone,” assuming that by your efforts you can “be reconciled to your brother” (Matt. 5:23-24).
Still, there are other times when the sin has a wider impact—it could be a sin against a number of brethren, or a sin that is known by and has affected a number of brethren, or a sin that has brought (or potentially would bring) shame or reproach on the church itself. When the effects of a Christian’s sin have permeated the body of Christ (and maybe even beyond), then to the body of Christ a Christian must make confession and seek forgiveness and reconciliation. This is what happened in Ephesus, as brethren came and acknowledged what had become widely known (i.e., they had sinned)—thus, they “came confessing and telling their deeds” and repenting “in the sight of all” (Acts 19:18-19).
If my influence can be sinful and cause others to sin even in matters of judgment (cf. 1 Cor. 8:9-13), how much more can my actions and my influence lead others to stumble when said actions are inherently sinful (cf. Rom. 14:23; Matt. 18:6)? Therein is the purpose of confession and reconciliation with our fellow brethren—that the soul of the one who sinned and the soul of the one sinned against may both be saved!