Halloween was such a problem when I was religious: I wasn't comfortable letting my kids celebrate anything about death or ghosts, but I didn't want to deny them the fun of dressing up and scoring heaps of candy treasure. What's a Christian parent to do? Enter "Harvest Festival" at practically every Evangelical church, where kids can dress up as animals or Bible characters (within reason, of course. I don't recall too many Jezebels or Salomes) & celebrate God's bounty! Come to think of it, that does sound an awful lot like any number of Pagan festivals celebrating the change of seasons, but I digress.
Looking back as an atheist, it is weird to me that I had any fear around Halloween. Wasn't my God an awesome god, powerful enough to protect my offspring from any demons that might try to enter them through unholy Halloween costumes or ghost stories?
Here is what the fear was really about:
DEATH & HELL.
There are many branches of Christianity, all with slightly different takes on salvation. Some are of the "Once saved, always saved" variety, while others believe it is possible to lose one's salvation. As you can imagine, the latter keeps Believers on the edge of their seat, hypervigilant lest one wrong move (or thought or word) should undo all of their righteous living and result in them being cast into The Pit. In addition, there is also the very real possibility that God might withhold His favor for some reason, allowing said Believer to die unexpectedly. To die without being in a proper state of repentance guarantees a one-way trip to that Lake of Unquenchable Fire.
In my practice as a religious recovery consultant, I interact with many intelligent people who have rejected religion entirely but remain plagued by the fear of Hell that was instilled in them during childhood. There is some good news on this front, however. Just as we have reached outer space and not found any evidence of a literal heaven, there has been pretty significant research done related to what lies beneath our feet - and no Hell has been discovered!
From whence cometh the stories of eternal damnation, fire, and brimstone? One need look no farther than the great Wikipedia https://en.wikipedia.org/wiki/Hell to learn the history of Hell's origins.
The problem is, phobias are not rational - and this includes stigiophobia or hadephobia (fear of Hell). Simply reading that Hell is mythological rather than literal will not undo decades of being taught otherwise. Additionally, when we learn something and the lesson is encompassed by fear, those beliefs become extremely tenacious. Indeed, my simply assuring clients that "There is no such thing as Hell" provides little-to-no comfort. The hard work truly must be done by the one recovering from such despicable teachings.