There is a difference between gospel-centered change and self-reformation. David Powlison describes it this way in his book Seeing with New Eyes:
No one can truly change who does not know and rely on gifts from the hand of the Lord. Since Christ is both Giver and Gift, attempts to change without grace are barren of the very purpose, power, and Person that change is about. Self-manufactured change does not dislodge almighty me from the center of my tiny self-manufactured universe. Still in the futility of my mind and the hardness of my heart, I only act a bit different.
Successful living without grace describes mere self-reformation: get your act together, save your marriage, get off your duff and get a job. Failure in living describes failed self-efforts: when you can’t get a grip, you despair. Christless, grace-less attempts at change conclude either with the praise of your own glory or with your shame.
I love the language of dislodging “almighty me” from the center of the universe. Whether you succeed or fail in your attempts at self-reformation, you are still focused on yourself. The one thing that is necessary for true and lasting change hasn’t happened: “He must increase and I must decrease.” (John 3:30)