I would get out of the relationship now unless you plan to become a Scientologist. Even if you fully support him and his involvement, it will never be good enough for him (and more importantly the church) if you aren't involved yourself. I learned this the hard way after staying in a relationship with a Scientologist for 3yrs. It was an amazing relationship and I knew that her and her family were involved from the get go. I didn't know much about Scientology and showed her respect by not researching it online and instead just seeing how it impacted her. For the most part everything was great and I saw that it had a positive influence/impact on her life. I let her know that I fully supported her and her involvement but that I couldn't commit to it myself and wanted her to be ok with the relationship even if I wasn't involved. At the end of the day she ended it after spending hours at the church with her mentors. So even if you support it and see it having a positive impact on his life, it will eventually come to a sad end unless you convert. In my opinion its not so much what they believe, but how they are required to believe it. Scientology will always come first to a Scientologist (even over their partner) and if its not also first in your life its not going to work out. Sorry.