I still think you can enjoy it without caring much about religion.
Without giving away any spoilers to the books, the parasites are only that on the surface. If anything, the books present a wary picture of religion, especially the last two Endymion books, but also a wary picture of technology.
As we have both read the books, it's notable that you associate pilgrimage with Christianity. This illustrates the point.
They're not at all incidental. The themes and the literal Catholic Church don't just make it into the books by osmosis, they're central to it and deliberate.
Like Gene Wolfe he's part of a pretty small group of US authors who wrote Catholic speculative fiction. Like Wolfe his writing is also fairly un-American. If Heinlein or Asimov are examples of archetypal US science fiction, Simmons is about as far as the other end as you can be, with the post-modern structure, the Canterbury Tales as a template for the story and so on.
I had recommended Hyperion to a friend, and they loved it. I recommended Canticle as a follow-up and they hated it. I never figured out how that can be.