I agree with you on principle here, but God can and has changed homosexual/lesbian orientations, but He cannot change pedophiles?
God can heal anyone of anything.
But the church should never put anyone who has sinned - to the point of harm to the helpless/themselves and criminalization - in the path of temptation. That's not denying a change. That's protecting the innocent and being a wise church.
I would be unhappy if my church put a person who has spent time in jail for embezzlement on the counting committee [counts money after church], financial secretary, or anyone directly in charge of the accounts of the church or handling the money directly.
If I were at a church that used real wine in their Lord's Supper, I would not want a reformed alcoholic being in charge of filling up the cups. That person in my church [we use grape juice] does that by themselves early before the church service.
It's not about God not healing people. It's about the church not putting a reformed person in a place where he or she could relapse. The church would be legally liable and people would blame the church moreso than the individual who relapsed.