One day the Vatican wakes up to the possibilities of science and embraces it with the fervour of a convert. Suddenly, it is possible to create "new men". Where the Vatican used to see sin, now they see biology, and biology can be changed.
In the past, willpower lead to habits. Repetition etched new neural pathways in the brain. People became "new men", the humans they aspired and practiced to be. There was plenty of backsliding.
But if the Vatican truly believed surgery or medicines could create this admirable humanity, could they make it required? Excommunication if you refused to become a "new man"? To be Christ via a tablet?