Why is it so rare to find complex depictions of religious characters and stories that take religion seriously?
Because this would appeal to a very niche audience, and there's no reason for TV producers to purposefully put themselves in this kind of corner.
Most Americans are religious. And there's no reason to assume that nonreligious people wouldn't be interested in such stories.
Many Americans who self-id as Christian don't go to church and don't really pray, which was my larger point. I just have a hard time imaging this kind of thing
working as part of the TV show unless religion was like, part of the premise itself.