My recent reviews of Infinite Space, Infinite God and Seven Archangels: Annihilation made me remember a few other books of that category which also give us food for reflection about faith. You can find my reviews here:
ongoing conversation about science fiction with a Catholic twist and this is an interesting list of books which are explicitly "Christian", have Christian characters, or deal with Christian themes, have been recommended by at least ten members of Christian Fandom
I know there was a fairly comprehensive list with comments about how the faith was portrayed at a Catholic science fiction blog somewhere in the past ... but I couldn't find it. I bet someone out there knows (the Curt Jester? Scott Danielson?).