Speaking of film, Derrickson says that the horror genre "distinguishes and articulates the essence of good and evil better than any other genre" and when asked about the fantasy genre, Derrickson said:
The evil within the fantasy genre tends to be threatening to the heroes within the story, but not to the reader -- or not to the viewer, in the case of cinema -- and that's why I think it's more palatable, and something that is more easily embraced for a lot of people. Because it does deal directly with good and evil, but it doesn't serve to actually render feelings of fear and terror within the reader, in the case of literature, or within the viewer, in the case of cinema.
I've enjoyed horror films and horror literature since my youth, a taste perhaps fostered by two English teachers I had when I was about 9-10 years old, Murray Bissett and Wilfred Noriskin, both of whom encouraged creative writing and imagination. Murray Bissett, in particular, read us ghost stories, and the boundary between ghost stories and horror stories is often hard to determine. One of the first stories he read us was The ash tree which sounded considerably more horrific to our ears than the author intended, since we pictured a ghostly undead revenant tree, which had resurrected itself from the ashes in the grate, or a forest fire, and planted itself, grey and ghostly with blackened branches, outside a house to haunt the inhabitants. It was only much later that I learnt that there were living, green and growing trees called "ash".
When I was in high school I discovered a two-volume collection of short stories in a book case at home, edited by Dorothy Sayers, called Detection, mystery, horror. The detection section went unread, the mystery section I read once, but the horror section I read again and again. Two stories in the collection stood out, The Wendigo and Couching at the door..
Not long after that I discovered Dracula, and The devil rides out, by Dennis Wheatley, both classic horror stories of their time. But after leaving school I read very few horror stories, mainly because they were so difficult to come by. There was a film, The innocents based on Henry James's ghost story The turn of the screw.
The genre has various names, or perhaps there are overlapping genres -- horror, supernatural fiction, ghost stories. "Supernatural fiction" seems to cover most of them. And in that category most of Charles Williams's novels seem to fall, with All Hallows Eve and Descent into hell being ghost stories, and Many dimensions having elements of classic horror.
But as I got older, perhaps my taste got jaded, and most of the "horror" stories ceased to horrify. There was a sort of "I've heard it all before" feel. Horror films were even less effective, with too much reliance on special effects and distracting one from the plot with "I wonder how they did that" thoughts.
Of these authors, Charles Williams was Christian, and so was Sayers, though she was an editor rather than an author when it came to horror, and did not write much herself.
Among more recent authors associated with the horror genre is Stephen King, but many of his books are thinly disguised science fiction, where the source of the horror seems to be something that came from outer space (Desperation, It, The tommyknockers). His Pet sematary, Needful things and Salem's lot are closer to classic horror in the sense of supernatural stories. But even these seem to be nihilist rather than Christian, as far as the examination of evil is concerned. The supernatural evil is just there, as in H.P. Lovecraft's Chthulu mythos. The actual struggle between good and evil takes place at a much more mundane and human level, in the lives of the characters. And when one sees it in that way, it can actually throw some light on the Christian understanding of spiritual warfare, as discussed in the recent synchroblog. So, for example, in Pet sematary the family of the protagonist is visited hy evil revenants, but the battle is not fought primarily between the protagonist and these, but within the heart of the protagonist himself. It is the devices and desires of our own hearts that lead us astray.
This can also be seen in Bram Stoker's Dracula. The vampire, for all his evil powers, cannot enter the house and harm the inhabitants unless one of the inmates invites him in. Or, as St Peter puts it, "Resist the devil and he will flee from you."
But for all its value in showing the battle between good and evil, horror is limited, because one becomes sated. Myth and fantasy go deeper, despite Derrickson's reservations. But I would like to issue a challenge to Derrickson: make a film of a Charles Williams novel. That would be a real achievement.