As old fogyish as it sounds, you need to watch what kids put it their heads. I wouldn’t suggest you take a young kid to this, as it paints religion in a very bad light.
What is said, is that so much of sci fi does that.
It's not at all 'old fogyish' - what parent doesn't instinctively want to protect their young from such an assault? The dilemna, unfortunately, i that we live in a very secularized society where teachers and friends hold sway over what Mom and Day have to say. That said, the best piece of advice for parents and grandparents is to read or familiarize themselves with the contents of these books so as to address any questions raised by precocious children who will see it, especially if their parent are against it.
Some of the best Sci-fi books, however, have religion in a very positive light, such as “Canticle for Leibowitz” and “The Mote in God’s Eye”. A.C. Clarke and Asimov, while being visionaries in the genre, wrote some very atheistic works. Also noticed the Sci-fi authors that disparage religion raely know what they’re talking about. Another case of “stick to science please”.