Thinking about this some more, Halloween has taken on a number of faces in the modern world.
There's the fun face with jack o'lanterns, costumes, trick or treat, parties.
There's the dark scary face, with monsters, ghost stories, and such
There's the spiritual face, with pagans (at least ones leaning Celtic) celebrating Samhain and some Christians All Saint's Eve and Day.
Interesting how one festival takes on so many aspects. Christmas has kind of fallen into the same, really.
The fun face with Santa and family get-togethers and such that is basically secular.
The spiritual face, with the celebration of the Nativity in Christianity and also some nearby pagan Solstice festivals (and Kwanzaa and Hanukkah are usually close by, too).
And, oddly, a bit of a scary face with the tradition of Christmas ghost stories, best known through Dickens of course, but English writer M. R. James wrote many of his fantastic ghost stories for reading during the winter holidays. Robertson Davies did similar during his tenure as master at Massey College and eventually collected them for publication.
And there's a "serious" face around stories like It's A Wonderful Life that kind of blend the fun and spiritual faces in various ways and degrees.
Not sure there's anything deep there, just a reflection on the evolution of holidays in our culture.