I've never met IRL someone who fully rejects all types of supernatural belief, as I do.
You have now. I think of all religion the exact same way as I think of Santa Claus, the Easter Bunny, the Tooth Fairy, Roman and Greek Gods, Harry Potter, etc.
And I don't mind sharing that belief, either. I'm not rude about it, I NEVER bring it up ony own, but I also won't politely accept their superstitions as a logical argument for ANYTHING. If we're doing something because God wants us to, then I'm against it. Show me a real reason that isn't a fantasy, and I'll consider it.
Religious reasons are the same as saying Mickey Mouse told me so, and I would have absolutely no problem saying "I'm not doing this just because your "God" says so, give me a real reason," no matter who is in the room. That's not being rude, being rude is demanding I do something stupid because YOUR psychopathic imaginary friend says so, and you're terrified that he will punish you if we don't. I'm not doing something I disagree with, just because you are afraid of your own imaginary friend. Go fuck yourself with your childish nonsense.
It helps that I'm self-employed, and my incompetent boss has the same beliefs as me.