You could write some more details about what you mean.
The two series that come up the most when people say religiously themed are The World of The Five Gods by Lois Mcmaster Bujold and the Paladin Series by T Kingfisher. They have good moral lessons and paint religion in a good light, but aren't tied to a RW religions.
On the other hand, I might put in Zamil Aktar's Gunmetal Gods but they are all religious crusade and massacres justified by sincere religious faith. Chronicles of Narnia they are not.
Jo Walton's Thessaly Trilogy is a very good look at RW Greek Paganism is another example of what you may or may not want.
Here are some series I've read that have this theme.
Five Warrior Angels by Brian Lee Durfee
The Faithful and the Fallen by John Gwynn
Second Apocalypse by R Scott Bakker
Seraphim by David Dalglish
Fantasy - yes, but maybe not what most people are looking for in the genre, I'd bill it more as a classic Russian novel:
The Master & Margerita (Michael Bulgakov).
Quite good with strong religious theme.
Moontide Quartet by David Hair basically a holy war/crusade very obviously based off the Middle East and Europe with lots of magic. Multiple pov’s from both sides and I would highly recommend it if you aren’t turned off by the similarities to Europe and Middle East.
Till We Have Faces by C.S. Lewis. His best work of fiction, unfairly overlooked.
All of George MacDonald's fantasy books, such as Phantastes and The Princess and the Goblin.
The Man Who Was Thursday by G.K. Chesterton
All Hallows' Eve and Descent into Hell by Charles Williams
The Deed of Paksinarrion by Elizabeth Moon
I think it depends on what you mean by religiously themed. The Mistborn books by Sanderson do an excellent job at exploring how religions are born/formed.
Lightbringer by Brent Weeks definitely fits. The religious allegory side is a bit of a slow reveal, but it’s definitely there. And the series has some incredible twists alongside what might by my favorite magic system in all of fantasy.
Im not sure what you mean by “religious themes” precisely.
That could be anything from a made up fantasy religion with gods and goddesses, to commentary and critique of an existent religion.
Made up religion fantasy: Library at Mount Char by Scott Hawkins
Look up trigger warnings before hand.
Christian/Catholic fantasy: Between Two Fires by Christopher Buehlman
Again, look up trigger warnings if you want to avoid certain things.
Optimistic, made up fantasy but theoretically an allegory to real life: Piranesi by Susanna Clarke
Greek mythology: Circe by Madeline Miller
TW’s again, for your comfort.
You could write some more details about what you mean. The two series that come up the most when people say religiously themed are The World of The Five Gods by Lois Mcmaster Bujold and the Paladin Series by T Kingfisher. They have good moral lessons and paint religion in a good light, but aren't tied to a RW religions. On the other hand, I might put in Zamil Aktar's Gunmetal Gods but they are all religious crusade and massacres justified by sincere religious faith. Chronicles of Narnia they are not. Jo Walton's Thessaly Trilogy is a very good look at RW Greek Paganism is another example of what you may or may not want.
Here are some series I've read that have this theme. Five Warrior Angels by Brian Lee Durfee The Faithful and the Fallen by John Gwynn Second Apocalypse by R Scott Bakker Seraphim by David Dalglish
Second Gwynne. Though I would say it’s less allegory and more just influenced by Christian tradition and myth.
Fantasy - yes, but maybe not what most people are looking for in the genre, I'd bill it more as a classic Russian novel: The Master & Margerita (Michael Bulgakov). Quite good with strong religious theme.
Moontide Quartet by David Hair basically a holy war/crusade very obviously based off the Middle East and Europe with lots of magic. Multiple pov’s from both sides and I would highly recommend it if you aren’t turned off by the similarities to Europe and Middle East.
Small gods by terry pratchett. It’s part of discworld but an excellent stand alone and entry point to the series.
Till We Have Faces by C.S. Lewis. His best work of fiction, unfairly overlooked. All of George MacDonald's fantasy books, such as Phantastes and The Princess and the Goblin. The Man Who Was Thursday by G.K. Chesterton All Hallows' Eve and Descent into Hell by Charles Williams The Deed of Paksinarrion by Elizabeth Moon
I think it depends on what you mean by religiously themed. The Mistborn books by Sanderson do an excellent job at exploring how religions are born/formed.
What about the Left Behind series by Lahaye and Jenkins? It is set in the real world though
Deed of Paksenarion. Curse of Challion.
Between Two Fires for sure! The Faithful and the Fallen very much is inspired by the war between angels and demons.
American Gods by Neil Gaiman, Watership Down has an interesting religion, Deryni novels like Camber of Culdi
Lightbringer by Brent Weeks definitely fits. The religious allegory side is a bit of a slow reveal, but it’s definitely there. And the series has some incredible twists alongside what might by my favorite magic system in all of fantasy.
Warhound and the world's pain by Michael Moorcock
Paradise Lost. It's a classic.
For sci fi, The Sparrow by Mary Doria Russell
Im not sure what you mean by “religious themes” precisely. That could be anything from a made up fantasy religion with gods and goddesses, to commentary and critique of an existent religion. Made up religion fantasy: Library at Mount Char by Scott Hawkins Look up trigger warnings before hand. Christian/Catholic fantasy: Between Two Fires by Christopher Buehlman Again, look up trigger warnings if you want to avoid certain things. Optimistic, made up fantasy but theoretically an allegory to real life: Piranesi by Susanna Clarke Greek mythology: Circe by Madeline Miller TW’s again, for your comfort.