Halloween has nothing to do with Christianity. The Romans dedicated the Harvest Holiday to Pomona, the goddess of fruits and seeds, and the Celts celebrated the summer's end with huge bonfires to evoke the blessing of the spirit world for the dark half of the year. Walking between the fires cleansed the soul for the winter. The practice probably dated back to the Picts and further into prehistory.
The following day was the feast of the dead.
For the dead are never dead in our hearts and minds, except for the Living Dead.
In Gaelic the walking dead are called marbhán siúil.
The modern usage is zombai.
Thankfully they are creatures of myth and not reality like banshees and leprechauns.
Nothing was scarier than the LIVING DEAD.