Several other classics are included: "The Quest for Saint Aquin", by Anthony Boucher; "A Case of Conscience" (the original short story, which is the first and best section of the novel) by James Blish; "A Canticle for Leibowitz" (the original version, much improved by the author for the novel) by Walter M. Miller. There are also a couple of good original stories by Gene Wolfe and Jack McDevitt.
I got a lot more out of this collection than I did from the collection of Jewish sf which I read last year, and I don't think it is just because I am Catholic rather than Jewish. The editors here have consciously sought stories that engage intellectually with religion, rather than being based on cultural stereotypes (though admittedly the latter are not completely absent). I think this anthology would be much appreciated by any sf reader with an interest in religion and a basic knowledge of Christianity, and it's a bit unfortunate that it was marketed solely to Catholics.