When I heard recently that Jennifer Knapp was coming back I was glad. When I heard even more recently that Jennifer Knapp was coming out I was grieved. Knapp's earlier work is excellent-- especially her first album, Kansas. It saddens me though that this professing Christian has embraced her sin as a lifestyle. Let me be clear though that my issue is not that she's sinned. I've sinned. You've sinned. We all still sin. The issue is repentance.
Those who have been truly regenerated by the Holy Spirit and are genuine disciples of Jesus still sin-- sanctification happens over a lifetime-- but when we sin the Spirit works to bring conviction and repentance. Repentance is a change in direction. We realize our sinfulness and need for forgiveness. We fight that sin by faith in Christ. Some argue against the practice of church discipline or any effort for spiritual accountability (ignoring the obvious commands in Scripture) by saying that we aren't qualified to be "sin police" since we are all sinners.
Once again, the issue is not that we are all sinners. Of course we are! The issue is that we all need to repent and if we really love one another we'd help each other to repent. Repentance recognizes the holiness of God and the deadliness of sin. It should grieve us when one chooses the love of sin over the love of Christ (erroneously they may reason that Christ loves them in spite of their sin so it is okay to keep on as they are). When one will not repent it bears evidence that they are not of the faith and stand unprepared for judgment. If we really love them we will intercede to help them see their need for repentance. For myself, I hope that if I find myself caught up in any tresspass then those who say they love me will show it by such intercession.
See: Galatians 6:1-2; 2 Corinthians 7:8-13; 1 John 2:18-24