Have you noticed how often Christianity equals Catholicism in science fiction and fantasy? Think about it – when was the last time the religious side of the story was represented by a Presbyterian, a Methodist or someone of Eastern Orthodox faith? But look at Daredevil – both in comics and on screen – The Sage of the Exiles, The Sparrow, or many other sf+f works – you’ll see Catholicism all over the shop.
I don’t think it’s because there are more Catholic writers than ones of other denominations in sf+f. After all, Protestantism is bigger both in the UK and the USA, the sources of most of my reading and viewing.
I don’t think it’s because Catholic beliefs are any more interesting to extrapolate from. If I was looking for a faith that does something unusual then I’d turn to the liberal Quakers, with their decisions by consensus, their evolving book of faith and their soothing/eery (depending on your perspective) silent meetings. And if I was looking for something full of angels, demons and holy warfare then I could pick pretty much any old school interpretation of any faith.
I think the reason may be that Catholicism provides a bunch of handy story-telling tools. The focus on sin and guilt creates obvious internal conflict for characters. The confessional provides an excuse for characters to say things out loud that would otherwise remain internal. The heavy use of ostentatious imagery and symbolic ritual creates striking visuals for television, comics and film – Quaker meetings are cool and all, but they usually look like a bunch of ordinary people sitting in a plain room, and much Protestantism looks like Catholicism light.
I’m not saying that the use of Catholicism in sf+f is necessarily shallow – far from it, Julian May built a whole universe around the dissident theology of Pierre Teilhard de Chardin. But I don’t think it’s generally chosen for its depth, and the attractions it provides for story-tellers are ones most other Christian denominations can’t match. Much as I’d love to read that Quaker sf story, if I want to then I’ll have to write it myself.