Great question, but I want to add one more thing to it, All Hallows Eve, or Halloween. They are all three related. They are also confused.
Some of the confusion has to do with language. We have a combination Greek, Latin, English and German words that makes for difficulty. As I noted above, Halloween is short for All Hallows Even. That wording, translated means All Holy One’s Evening. It is the day before the Day of All Holy One’s. That’s just a different way of saying the eve of All Saints Day. How Halloween got all mixed up with ghoulies and ghosties and hobgoblins is a strange combination of middle ages superstitions and excessive Roman Catholic theology. Way back yonder, with the Black Plague, death was so much of a present reality that people were quite obsessed with all of the possibilities surrounding the question of what became of the bodies, spirits and souls of the dead. That becomes especially weird when you begin to take each element separately. Sometimes it got so complicated that they were talking about each body part independently. For instance, what happens to a dead man’s head if it is separated from his body in death. Does it lead a different sort of existence in the next life? And what happens if the disembodied head belonged to someone so evil that they are rejected by both Heaven and Hell. Welcome to Jack O’ Lantern. It gets very complicated.
Originally, All Saint’s Day was envisioned as a day to commemorate Christian Martyrs, those who had died under persecution of the faith. As the world became more Christianized, it became more popular to remember Saints, not only for what they died for, but also for what they lived for. Today, on All Saints Day we commemorate all of those who lived and died heroically for their Lord. Typically we consider All Saints Day to be especially for those who have attained the Beatific Vision, or who have ascended fully into heaven.
From very early times, the word “saint” came to be applied primarily to persons of heroic sanctity, whose deeds were recalled with gratitude by later generations. Beginning in the tenth century, it became customary to set aside another day–as a sort of extension of All Saints–on which the Church remembered that vast body of the faithful who, though no less members of the company of the redeemed, are unknown in the wider fellowship of the Church. It was also a day for particular remembrance of family members and friends who had died.
Though the observance of All Souls Day was abolished at the Reformation because of abuses connected with Masses for the dead, a renewed understanding of its meaning has led to a widespread acceptance of this commemoration among Anglicans, and to its inclusion as an optional observance in the calendar of the Church.
The Church has traditionally been divided into three parts; The Church Triumphant (those who have fully attained Heaven), The Church Militant (those who are still walking around on the Earth), and The Church Expectant (those who have died and have not yet ascended to Heaven). The scriptures call the place of the Church Expectant; either prison, or the place of judgment, or the place of cleansing. I prefer to call it Purgatory, the place of cleansing. Do you remember what happened to Dorothy, and the Tin Man, and the Scarecrow, and the Cowardly Lion when they got to Oz? They all got spruced up, cleaned up, freshened up. Even Toto got a bath. That’s Purgatory.
It raises the question; How do we know whether someone is in Heaven or in Purgatory? Some people would claim to be able to tell, but in reality it is all speculation. It is all hidden behind the veil. I think it safe to say that they are all in the hands of God. Sometimes we want to know things that God has kept hidden. That was the beginning of the problem in The Garden. It is best to leave God’s business up to God.