Lately I have started to seek out being around more of those couples who actually have a pretty steady relationship, there isn't some big blowout drama that comes up every month, or even a potential one that's brewing. Something I have seen with all of them is that each person has had a very deep connection with their spirituality or religion, whether it be Episcopalian, Lutheran, Wiccan, Pagan, Jewish, Agnostic, Atheist, etc. Even in some of these couples, both partners don't follow the same religion or even have the exact same beliefs. However, both partners respect one another about what they do believe and don't make it an issue when there's a difference.
One couple that I absolutely love to death might be considered on the opposite ends of the spectrum when it comes to some of the details about what they believe (although they have much in common as well), yet the both of them get along great because they both have learned a thing or two from their own spiritualities and religions about respecting one another. There is another couple I know that is very dysfunctional. One has pretty much always made it clear since I've known him that he wants a nice boy of his own faith, and if he can't find one, he'll just work to get the guy he's dating to convert. If one is open to trying out a different religion or spirituality and it is something that they want to do, then by all means they should do some exploring. It has to be for themselves though, not to make someone else happy. It should never be because a partner pressures them into doing it. I know for myself that I like where I am right now on my own spiritual path and I am not going to let someone else change it.
I really would like it if I could find a nice Episcopalian to get together with, but barring that, he's gotta at least respect my beliefs, and support me and my involvement with my church (and it wouldn't hurt to go to a service with me once in a while ;-) ). I would do the same for him.
Admittedly my experience of seeing these trends are likely biased because much of my sampling comes from folks I know at my church.
Ultimately thout, if a couple can't respect one another on a difference of spirituality, than what else are they not respecting each other on?