The problem is, that if you allow this 'advert' to take place, you could then run into a problem with other religious sects including violent ones also wanting to proclaim their beliefs. What you do for one you would have to do for another, which could lead to all sorts of difficulties. I think too, that a lot of people would find this embarrassing, and would either talk, shuffle, or even catcall during this episode. All in all, the cinema is not the right place for religion, unless it is a specifically a religious film. Carol services you can walk past, or listen for a minute or two; in the cinema you can't 'escape'!!!