[Elspode]

There is very little in Christianity that wasn't around in one form or another before they commandeered it and tailored the mythology to suit their particular needs.

And, yeah, All Saint's Day was placed where it is to counter the night "when the veil between the worlds is thinnest, and the spirits of our anscestors are near". Thus, Samhain became "All Hallow's Eve" (since it was the night before All Saint's Day), which we now colloquially call "Halloween".

There is much interesting history behind the relationship between the beliefs and practices of the ancient peoples of Europe and the influx of Christianity. Killing off witches and Pagans was once thought to be a good idea, you know. And, if Ashcroft has his way, perhaps it will be thought to be a good idea again some day...