Life is lived in moments.
The veil between the worlds was viewed more or less as being open Halloween night, and human beings were not the only beings in the underworld which was not a deep, dark, dank cavernous region. It was viewed as being much like our world, but better kept, blessed as it was the abode of the gods.
Your ancestors could influence your fortune, for better or worse. In part because of what they themselves could do during this night, but also because of what they could tell the gods. They carried your respects, or news of your disrespect, to the other side.
If I call my dad a jerk, he will rat on me to the gods? Yes, which could mean you wind up dying over the winter, but are you familiar with the concept of taboos? The spirits had something called bans, laws governing their behaviour while in the world, sort of like taboos for the dead. So not every departed ancestor would have equal influence in the other world. If your dad was notoriously dishonest, he would have trouble communicating on this night and his words would carry little weight with the gods in the other world.
Some spirits were so despicable they were not welcome in the underworld. This is the source of the notion of the evil dead walking the earth. They were not welcome in the presence of the gods, but even they remained subject to the laws of the dead and had certain additional limitations. So another role for the witch on this night was that of exorcist, bouncer for the evil dead. The additional limitations the evil dead were subject to amounted to one simple idea. They had to continue to bear the weight of their sins.
The dead get awfully drunk on Halloween? Actually, yes they do. Traditionally, as do the living alongside them.
What or who governs the laws? And who determines what is sin? Betrayal of your family and by extension your tribe. Anything that would mark you as unsafe, dangerous, hateful to the people, was effectively sin. They didn’t adhere to the Christian view,
Is there some higher being in control? Yes. The gods followed a simple social structure that mirrored that of the tribe; a chieftain and various other members of the divine tribe. I am speaking in general terms because these beings went by different names though they had similar descriptive traits. The origin of the idea that witches eat people, actually came from a crone goddess who herself still didn’t eat people, but she was the equivalent of the Grim Reaper.
The reason they associated witches with this reaper crone is she was also the one who gave the lore of healing, staving off death, inspired people with the understanding that would lead them away from a death come too soon. She was among other things the grey mare, or white mare (perhaps the origin of the term nightmare), but her role was more of a guardian than anything else. She protected the returning dead from the evil spirits, as well as protecting any of the recently departed on their trip to the other world. This was another role of the mortal witch, psycho-pomp, guide for the dead.
A shaman? Basically.
Your thoughts are welcome. Be well friends.