There are many biblical principles that have been defined by our traditions and preferences, some resulting in confusion and division in the body of Christ. I believe that "repentance" is one of these principles that has been reduced to its lowest and least powerful denominator when it is applied only to our behavior.
I remember, as a young believer, the way that my tradition addressed repentance. It went something like this... Father, I think I really messed up this time, and the pastor says I need to confess and repent of my sins. He also said that I need to feel really bad and remorseful or it's probably not real. So-o-o, I'm confessing that I've sinned, and I feel really, really, really bad about it. And I'm really, really sorry about it. So please forgive me and I promise I'll never, ever, ever do it again.
Hmmm. Pretty powerful stuff, huh? Of course I'm exaggerating a bit to get my point across, but I think my point is pretty close to home. In this case, repentance was reduced strictly to a remedy for my poor behavior. The goal of this exercise was for me to recognize my deviant actions (sins,) agree with God (confess) these sins, ask His forgiveness, and therefore be free (at least until next time) from the consequences of my terrible behavior and have unfettered relationship restored with my heavenly Father. Not a bad plan... except that repentance is SO much more than fixing errant behavior.
Let's DO Life!