Sacred Music

Please delete if not allowed. Title pretty much says it all. Lately I've been getting a lot more into sacred music and I remember once an acquaintance was telling me about a prospective new job at a Baptist church (he's an organist and was at a Catholic church) and he was saying that one had much more complicated music than the other. Can someone point me to more resources for learning more about this kind of info? I'm a classically trained pianist so I know about the Reformation, Martin Luther, Bach, etc. but my knowledge is pretty surface level.