One of the biggest reasons that the gospel (and gospel worship) appalls men is that men don’t want to forgive others.
The good news is that God sent His own Son into the world, born of a virgin, fully God and fully man, who lived a sinless life and then was crucified unjustly as a substitutionary sacrifice. He died for our sins, was buried, and rose again on the third day. His resurrection confirmed that the Father accepted His work and enables Him to forgive those who confess and repent. In Christ, all who believe are forgiven.
What kind of God would go through all of that in order to forgive rebellious people? A God who loves to forgive, who is glad to reconcile with enemies, who eagerly pursues fellowship with men. What does that have to do, though, with how we treat other people?
We cannot worship God without becoming more like Him. We cannot draw near to Him, see what He is like and see that He likes to be with us without also realizing that we are called to do likewise. The gospel of God flows downhill.
So Paul said that believers must forgive each other, “as the Lord has forgiven you, so you also must forgive” (Colossians 3:13). Jesus taught us that “If you you do not forgive men their trespasses, neither will your Father forgive your trespasses” (Matthew 6:15).
Confessing our sins in our worship service is a threshold. If we understand gospel confession correctly, not only are we being forgiven and cleansed by Christ, we are making a commitment before Christ to forgive others. Not everyone is eager to forgive others. We prefer holding on to our grudges and pettiness and criticisms. Getting forgiveness from God isn’t offensive until we realize that it also requires giving it to someone else. That’s yet more proof that we needed and still need the gospel of forgiveness.