You are in a rough situation bud! I was engaged to someone for 5 years who dident like the fact that I smoked pot and always gave me shit for it, but when she wanted to smoke it on vacation or randomly everything was O.K. You are who you are, and if the pot is not impacting you-or your marriage in a negative way then I do not see the problem. But tell her the truth ASAP, TRUST ME, lieing about it and not telling is a very very fine line and I never got anywhere by lieing about it. Tell her, I went to a very strict adventist school for most of my life when I was younger and I understand what you mean about the christtian girl thing and the whole stereotype. Good luck and BE HONEST! tell her!