This is a very odd series that requires a lot of you as a viewer. My guess is that most will not make it through all six episodes. That is a pity, because "Apparitions" is not a TV series with sequential episodes but one long story, told in six parts. And, taken as what it is, it's one of the best such stories ever told.
I don't much *like* the kind of story it is, but I understand it. It's *very* much like William Peter Blatty's "The Exorcist" and "The Ninth Configuration." Those were Catholic stories, too, about the question of faith, and the questioning of faith. But all three fall into a genre I would call "religious emotional drama queen fiction." That genre is about writers trying to manipulate audiences by showing them over-the-top miracle and possession stories to push their buttons and get them to associate those pushed emotional buttons with having had some kind of religious epiphany.
Ordinary life and ordinary questioning of faith aren't *enough* for these writers. They have to "paint large," and can seemingly only believe in God or attempt to sway others into believing in God by creating larger-than-life situations based in conflict between good and evil, personified as a conflict between the man of faith and Satan. Such stories are IMO the spiritual equivalent of sappy romance fiction and manipulative emotional tearjerkers. There is little about them that could be described as "subtle." That said, I think that "Apparitions" is pretty *good* religious emotional drama queen fiction. It is FAR better than Blatty's "The Exorcist," and FAR more intelligent. The cast is excellent and the writing more so. But it's still religion dressed up like Carmen Miranda. I prefer subtler stuff.