Maybe using religion in general, and not pointing to a specific one, would be less likely to alienate a reader. I'm not sure. I personally didn't have a problem with the mention of Christianity; if we view it in from a wholly objective way, regardless of the fact many of us are Christians, we can admit many things were tacked onto the religion that never appeared in the primal teachings of Jesus Christ or important disciples of that era.
I am going to start reading this e-book again. A few days were spent taking care of mundane, yet demanding tasks like cleaning the house and sorting out paper work. It's always nice to return to a good piece of informative writing after some work.