Frankly, I don’t know many people who are “constantly confessing their sins,” but I know what you mean. The truth is we still fall short of the glory of God in our practical walk before Him.
I believe that when a person comes to Christ, he confesses his sin and is forgiven. We are made alive in Christ where before we were dead in trespasses and sin. We have a new relationship. We have been reconciled to God through the blood of the Lord Jesus Christ.
When we sin, we break fellowship with God. We still have a relationship with Him, but sinful actions result from a heart that chooses to go against what we know is right before God. The confession that John speaks of is the confession of these sins (see 1 John 1:9). When Adam sinned in the Garden, he recognized that something had happened, and he ran away from God. We do that, too. We are like sinful children who need forgiveness for anything that comes between ourselves and God. Daily, (sometimes many times daily) we need to confess our sin and get back to walking a right path with God. Grace has forgiven us, and provided for us a Savior who makes that possible. Confession enables us to continue to move forward in our continued fellowship with Him.