I’m not saying that you have to be religious. But if you find those topics and related symbolisms rather uninteresting in your sci-fi, then the books may not be for you.
People are interesting, and religion is a thing people do.
In this case there is quasi-religious imagery but you as the reader aren't actually supposed to be mystical about the god/devil in the story the way the characters themselves are. It's not C. S. Lewis
I mean, it's not my fandom, but Catholics do have a wicked sense of symbolism and decoration. Hyperion wouldn't be as colourful if Simmons used a bunch of Evangelicals instead.
So the fact that "decoration" would be present is unsurprisingly, as Beauty in this reality can help to lead to greater reality of Truth and Goodness as well. It's why there have long been traditions with art, music, architecture, etc, in Catholic culture.
† God is Truth, God is Goodness (itself), and God is Beauty. (God is Love as well.)
There really is a huge stockpile of stuff there to build into fiction.
There's a whole crazy universe of occult-like lore within Catholicism that a subculture of Catholics really get into, it's pretty wild, often quite macabre.
I have a couple of those types in my family. The way they talk about praying to specific saints is like they're paladins in an RPG using divine magic.
Then there's the whole thing where the church has bones of long dead saints encased in ornate reliquaries that supposedly dispense miracles.