It certainly couldn't hurt to talk to the pastor. I agree with Mr. Silver that some churches don't seem to mind, while others do. When in doubt, ask for permission or park elsewhere. There's a church lot that some cyclists, including myself, use periodically. They're used to us and don't seem to care, but I wouldn't park there on Sunday. We often use church lots for our club rides, but we get express permission to do that--given the number of cars and liability issues.
When I first started riding, I often did a ride that was marked and maintained by a local bike shop. Instead of parking at the shop and having to cross a busy street, I would instead park in the adjacent neighborhood that is along the route. A homeowner spotted me once and asked only that I not park near his mailbox. Fair enough. A few months later, however, that same man approached me and told me that I'd been the topic of a recent HOA meeting. He'd been enlisted to inform me that I wasn't to park in the neighborhood--that the streets are for residents and their guests.
I was too stunned and tired to tell him to go jump!!!! The neighborhood isn't a gated community and last I checked, I'm free to park on a city street, even within a subdivision. It really burned me up that someone would be that petty. Plus, after having talked to the bike shop about the situation, we both agreed that the HOA was probably just a front and that it was really just this guy's beef with me. I haven't parked there since, but mostly because I don't do that route much anymore.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher