I've had a few Mormons round here try and convert me and even if I was religious that would have been the sticking point. Their Law of Health/Word of Wisdom as supposedly given to Joseph Smith may state that the body is a temple and that and that by refusing such things as alcohol, tobacco, recreational drugs, tea and coffee you are closer to God but there is no way I could exist without blood in the caffiene stream.
I did notice that asking about Cola did confuse the hell out of them as it also has caffeine in but isn't mentioned in the Law.

Asking about the polygamy or Warren Jeffs was also a no no