The End of the world
The eighth season of American Horror Story follows a post-apocalyptic storyline, brought on by none other than the Anti-Christ himself. This entire season is heavily influenced by Christianity, being that the term "apocalypse" has carried a religious connotation throughout history. The apocalypse is also a highly prevalent theme in horror genres, thus bringing the connection between horror and religion further [11]. Below, you can watch the season's opening title sequence in which a number of religious symbols can be seen [12].
So, not only is the entirety of the season based on a religious theme but even more so, the season is centred around character Michael Langdon, the perceived Anti-Christ. In the third episode of the season, called "Forbidden Fruit," a number of religious symbols can be seen. One of the key aspects that carry religious connotations is that during the episode, a number of secondary characters are poisoned by apples.
The apple itself is a huge religious symbol, for its connection to the Book of Genesis and Adam and Eve. Later on in the episode, Langdon summons his father, the devil, in the middle of a pentagram, as serpents appear out of thin air. Again, another religious symbol in the serpents as related to the Book of Genesis.
By this point, audiences will start to see that this episode is essentially a re-creation of the Book of Genesis. For context, below is a trailer for "Forbidden Fruit" [13]. In this trailer, Langdon recites part of the Ten Commandments, once again placing religion - a highly recognizable aspect of religion at that - in a horror context. Bible verses themselves are common in horror genres, often used as a call for salvation [14].
The question that arises from this episode, and from this season in its entirety, is if the religious symbolism present is actually integral to the plot, or if the religious themes were added in as a "filler" (an aspect of the plot that is not necessary for the storyline to be cohesive). Frequently in the media, religion is incorporated into a plot to bring an identifiable nature to the story. People are more likely to understand the plot and relate to it if something that is familiar to them, ie. religion, in this case, is a part of the television show/movie, etc [15].
The problem with this is that by adding religion into a horror context when religion is not integral to the plot, can in some ways, trivialize religion and use it as a "prop" of sorts. When religion is used to evoke terror or fear in a person, it may negate the aspects of religion that people find comfort in, have faith in and believe in. By placing religion in a horror context, the comforting aspects of religion are stripped away.
In this case, because the entirety of the plot is based around religious themes that persist throughout the whole season, the show does not appear to be trivializing/commercializing religion in any way.
It does not seem that they are using religion as an "additive," because the religious aspects are a constant variable in the season, not just something that's been added in to encourage viewership.
However, this does not answer the question as to whether or not the creators of American Horror Story are being disrespectful in using religion in a show about horror - even if they are using religion as a central theme.