Book of the Long Sun’s “church” is different, it’s the story of an artificial faith discovering something closer to the Truth than what they have. It’s obviously based on Catholic clergy and organization, but there are vast differences, including theology. There is a pantheon of “gods”, for one thing.
I am ashamed to say that I have never read Canticle despite hearing good things about it all my life and being a sci-fi/speculative fiction fan. I will go to the library and check it out.
My favourite authors are Jack Vance and Gene Wolfe, for my money there’s nothing I have come across yet that can touch those two.
Freegards
NPR Theater (or whatever it was called back then) did a multi-part radio-play adaptation of Canticle some time back in the late seventies or early eighties--and it wasn't at all bad, as I recall! It used to be available on a CD set, but I believe it is available somewhere online in a streamed or (marginally legal) downloadable mp3 format, if I am not mistaken. It would take probably as much time to listen to the thing as to read the book, but at least you'd have your hands free for work.
Didn't Jack Vance write The Humanoids? I read that (at a friend's recommendation) way back in what used to be called "junior high school" in the sixties--and it had the salutary effect of putting me forever on my guard against people aggressively "doing me good" by their lights, and completely contrary to mine, and my values. I have no memory of what Vance was up to, but that's what I took away from the book.
I just don't read much science fiction--or rather, I cycle through my comparatively small collection of favorites, over and over again, when I get the SF bug. I'm partial to Alfred Bester's The Stars My Destination and The Demolished Man, and though I'm not a big Greg Bear fan, I do enjoy The Forge of God with its increasingly chilling end-of-the-world vibe--and Niven & Pournelle's space-opera potboilers. I used to like Asimov, Clarke and Bradbury when I was a kid, but they generally give me hives now.
What I'm looking for from fiction is a certain kind of experience. Sometimes science fiction provides it; most of the time, it doesn't. If I could quantify what I'm looking for, I could save myself a lot of time--but then I'd probably never have the joy of finding things that are better than what I was looking for!