h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

What's the origin of it all, then?

Is Hallowe'en an attempt by the church to hijack Beltane, the old celtic year's end?

Is Guy Fawke's Night part of the same scam - find a good reason to have a big fire so that people forget why they used to do it?

Where does trick or treat come into it? It may be viewed as just american commercialism but how did it originate? Is it in fact a left over from the middle-ages that everybody else has moved on from?

Where else do they do Hallowe'en?

In Japan ghosts are believed to be unable to say the syllables mo & shi. When meeting somebody on an unlit road it became customary to call out moshi moshi to reassure the other person that you were alive - and challenge them to do the same.

Nowadays Japanese people still answer the phone with "Moshi-moshi".

Hallowe'en is actually an attempt by the church to hijack Samhain.

Beltane[Mayday] was hijacked by the church and turned into LadyDay, a much more innocuous festival than Beltane was originally...

I am reminded of the tune from Camelot:
[sings]
Tra-la, it's May, the lusty month of May,
That lovely month when everyone throws self-control away...
[Oh dear, I think I feel a Beltane article coming on]

Re: fires
There is always a fire. [Keeps the saber-tooth tigers and woolley mammoths away]

For more detailed answers to these and most of your other questions, see http://www.h2g2.com/A189470

moshi, moshi

I think bluDragon answered your questions. Thanks for stopping by and I'll add that bit about Japanese ghosts - pretty cool!

Surprised you had no mention of Pan here. Stolen to represent one of the churches most sick concepts, that of the devil. Pan was actually a god of nature in olde english custom, and celebrated by the bunch of loonies known as 'The Morris Dancers'. He had the legs of a goat and head of man complete with spendifourus horns growing from his head.

Can't fit 'em all in...

What the Christian church stole [er...'adapted'] from other religious celebrations is a much larger subject than there is room for in this forum.

That's a whole 'nother article.

PS Pan and Bacchus: two of my favorite gods