Each of us has the choice to attend the church we want to, or none at all. Separation of church and state allows for religions to have their own set of rules as to whom they will accept and who they won't, and the practices they support and the ones they don't. They will continue to be able to do so.
I always tell myself that when you're playing a character, pretend they're on trial and you're giving the best witness of their life. You really need to think about every element of the character and represent them properly, as if they were a real person. You want to give 100 percent of what they're worth and what they deserve as people.