My husband is Catholic too although not all serious and pro-life about it (I couldn't deal with that!) I have had a few times where I brought up the latest bullshit of the Catholic church and he kind of just didn't want to hear it. I didn't want to push him about it although I did get mad when he gave money to the church on one of the rare occasions he actually went to service.
People talk about deconverting people, challenging people, and I like to have debates and all that, but we also do interact with theists in our lives and for me if I always tried to challenge and deconvert everyone it would be too much like trying to turn everyone into me. I don't really think I am that great that everyone should be like me, and since my views change throughout my life this becomes hypocritical anyway. He believes in God and it makes him happy...actually, even though I have no intention of becoming religious, I kind of like this about him. It's one aspect of his overall positive personality. How is your boyfriend's outlook other than just being theist? If the person doesn't have the usual religious baggage, sometimes believing in God isn't that big of a detail.