I’ve had this open in a tab for long enough that I no longer remember who I got the link from, but: back in 2009, the blog Only a Game did a series of posts on religion in various science fiction texts. Not invented religions, but real-world faiths (though sometimes in future-adapted forms), and the ways in which books or TV shows or movies either represent the practice of faith, or grapple with the concepts behind those faiths.
The series starts here with an introduction (which as a second part a few posts later); the first actual discussion of a text is here, tackling Frank Herbert’s Dune. Unfortunately, there doesn’t seem to be a good way to link to the series specifically; the only tag they have is “serial,” and since the blog seems to do a lot of serial discussions, that pulls up a whole swath of more recent posts. But if you start at one of those two points, there are links at the bottom leading you onward to later installments, so you can skip the intervening entries on other topics.
I’ve touched briefly on the subject of religion in science fiction before, noting that the dominant message sent by SF as a whole seems to be that we’ll have gotten over that religion thing by the time the future arrives. There are exceptions, of course, texts that don’t assume the future will mean jettisoning faith, but they do seem like exceptions to me. And I suppose that view makes sense if you assume the primary cause and purpose of religion is the need to explain why the world works the way it does, and if you also make the corollary assumptions that 1) eventually science will be able to explain all of those things much better and 2) we are inevitably moving toward more science, not less. But I take issue with all three of those assumptions: contra Frazer, I think religion isn’t just for explaining the world’s functioning; I also think there are issues (like ethics) that science is poorly-equipped to handle*; and I know way too much about historical instances where scientific knowledge was lost to assume we’re just going to keep climbing that hill. If you define SF narrowly as featuring more advanced tech than we have now, then sure, clearly the future as seen in SF will not have to deal with the question of a new Dark Age. But I still think it’s facile to assume the impulse toward religion will have vanished along the way.
It will have changed, certainly. I never read more than the first Dune book, so until I read these posts I didn’t know Herbert had explored “Mahayana Christianity” and “Zensunni Catholicism” as speculative fusions of current religious traditions. I’d love to see more books that do something like that, imagining futuristic Buddhism or the Church of Christ Digital or what have you. So if you know of any, please recommend them in the comments.
*Please note that I don’t think religion is the only source of ethics. Atheists are perfectly capable of coming up with reasons not to steal from or murder one another; philosophers have been hashing out the issue of ethics for ages, and not always from a religious starting point. But if people have continue to have questions about why evil exists, or what their obligation is to their fellow man, I don’t think they’re likely to find satisfactory answers in string theory.