His belief is that Halloween was All Hallows Eve. And that the important days on the calendar are Nov 1 - All Saints day - when Catholics observe all Saints i.e. those who are in heaven, and Nov 2 is All Souls day - when one recognizes all those who are still in purgatory - in the hope that they will make it to heaven with the help of prayer.

He claims 17th Century protestants tried to ban All Saints day because it was Catholic. They claimed at the time that the Catholic belief of purgatory is incompatible with the Bible and was actually a Pagan belief. By taking away purgatory, any ghosts or goblins and recognition of spirits must be banned as paganism. (This is relevant, because the 17th Century was a time when objectivity was considered a gold standard and the ideas of 'proper' science were being developed. At the time, subjectivity (i.e. recognizing the unobservable) was considered irrelevant and akin to superstition. Imagine how mediums who can see the dead, fared in such an atmosphere.

So the persecuted Catholic emigrants to USA revived it, because there needs to be a day of recognizing the dead, whether they are good ghosts or demons - the plan is to pray for all of them. If one believes in an afterlife, then one should be concerned for soul welfare.

Witches and Wiccans have meanwhile paganized Halloween, which was a vigil for All Hallows tide.

HE claims the trick-or-treating was a Christian tradition, of bands of children going door to door, receiving soul-cakes, in exchange for prayers. The dressing-up is meant to scare the demons away, and confuse the dead who are likely roaming around. Also it is a disguise, so that those spirits will not recognize one, even as one is meant to pray for them the following day.

The solution is perhaps All Saints party - which is cute, but go ahead and celebrate Halloween.