Normally, filmmakers would just write a script and cast people to act as certain characters in the story. But in my way of doing things, I have the actors in my mind already, so I'm trying to borrow something that's unique to them. The characters have a very natural connection to the actors themselves.
People are always pleased to indulge their religiosity when it allows them to stand in judgment of someone else, licenses them to feel superior to someone else, tells them they are more righteous than someone else. They are less enthusiastic when religiosity demands that they be compassionate to someone else. That they show charity, service and mercy to everyone else.