I have to agree with CYP
My husband was inactive when we dated. I had no idea he was going to get back into the religion when we got married. Then, everything went to hell. Everything you do and say will be under a microscope and picked apart. If you were to get married, who's to say he won't haven't a sudden sense to get back for the sake of family, children, etc. If you are that serious, I would maybe just put my foot down and say, I love you, but not your religion, so please don't ever ask me to be a part of it, only part of your life. That of course, is if you ever get that serious... I do wish you the best of luck though!