Ancient History
Halloween is the festival of the dead. After the flood of Noah, the anniversary of the destruction of the earth became a type of Memorial Day. Originally to show respect to God, but then perverted by Satan to the worship of him as the god of the dead. We see it in its full form in Sodom. It is one of the reasons God destroyed Sodom.

Note: Jasher is recommended reading by the Bible. see Joshua 10:13 and 2 Samuel 1:18.

Jasher 18:11-13 In those days all the people of Sodom and Gomorrah, and of the whole five cities, were exceedingly wicked and sinful against the Lord... 12 And they had in their land a very extensive valley, about half a day's walk, and in it were fountains of water and a great deal of herbage surrounding the water. 13 And all the people of Sodom and Gomorrah went there four times in the year, and with their wives and children and all belonging to them, and they rejoiced with timbrels and dances. etc.

In modern day Witchcraft and Satanism the four holidays are still observed, the chief of which is Halloween.
The Hebrews went by a lunar calendar. The months started on the new moon, so most festivals were on the fifteenth, or on a full moon.
God ordained, in Leviticus 23, the Feast of Tabernacles on the fifteenth of the seventh month.
After the kingdom split into Judah and Israel, in order not to have Israel's money flowing into the southern kingdom of Judah (where God's holy temple was) Jeroboam instituted Halloween (full moon of the eighth month, or October), in place of Tabernacles (full moon of September)

I Kings 12:28-32 28 After seeking advice, the king made two golden calves. He said to the people, "It is too much for you to go up to Jerusalem. Here are your gods, O Israel, who brought you up out of Egypt." 29 One he set up in Bethel, and the other in Dan. 30 And this thing became a sin; the people went even as far as Dan to worship the one there. 32 He instituted a festival on the fifteenth day of the eighth month, like the festival held in Judah, and offered sacrifices on the altar. This he did in Bethel, sacrificing to the calves he had made. And at Bethel he also installed priests at the high places he had made. (NIV)

At this point there were the people and priests who worshipped Baal and the others who stayed loyal to The one true God. After the 10 tribes were freed from their captivity, they along with some of the Assyrians and possibly some Persians migrated to Europe and became know as the Celts. Some Celts settled in Britain , Ireland, and Scotland, were most of our information comes from concerning the Celtic priests called Druids. By the time the Gospel came to Britain, c. AD 40-60, the Druids that remained loyal to God immediately accepted Jesus as Messiah and as the fulfillment of their religion. From that time onward only the Pagans and their abominable practices remained.
Most of the practices of Halloween come from the pagan side of the Druids, which in turn can be traced back to the worshipers of Baal and Ashtroreth, among the Israelites, Zidonians, Egyptians, and Philistines. Later the Romans, sometime before the fourth century, combined their festival of "Pomona," the goddess of fruit and trees with the festival of Samhain. This is were bobbing for apples came from. In Ireland today its still known as "oidhch Shamhna" or "Vigil of Samhian" The pagan priesthood of the Druids in Ireland and northwestern Europe believed that Samhain {Sa-ween as it is pronounced}, the Lord of the dead {Satan} who controlled the underworld would gather together all the souls of those that died that year to purge them of their sins by transmigrating their souls into the bodies of certain animals for a time, a type of Purgatory, before they could go to Druid heaven. He also could be coaxed into giving a lighter sentence by gifts and prayers.

Practices
BONFIRES: {anciently called Bone Fires} were then the way to predict the future. A human being or animal was placed in a large wicker basket and burned to death. The pagans believed that the way he died and the form of the charred bones, like tea leaf reading, would tell the future for the next 12 months.
WITCHES: Pagans and occultists practice magic on Halloween. Whether or not you believe in magic is not important. Their are people who do believe in magic, and they can be dangerous.
BLACK CATS: were supposed to be familiars. {spirits who possessed animals and worked with witches}
JACK-O-LANTERNS: On Halloween night Druids would sacrifice humans to demons to gain more magical power. Jack-o-lanterns, originally made out of turnips but in America the pumpkin came to be used, would be used for lanterns. The candle was made partially from the fat of the human victim. Each Jack-o-lantern you would see means a loved one was sacrificially murdered.
TRICK OR TREAT: on Halloween night the people would set food outside to placate the spirits who were always hungry. If you didn't treat them with something they liked, they may be angry and punish {trick} you.
COSTUMES: If you dressed in a costume that represented one of the beings he might be more friendly and give you more magical power.
Ghosts. Goblins, Fairies, Demons, Sprites, and Spirits were just some of the beings they thought they could contact. Some were supposed to be good while others were evil.
Other Occultic practices associated with Halloween and Witchcraft are:
Palm reading, crystal ball gazing, Ouija boards, channeling, seances, horoscopes, and the wearing of Amulets and Talismans {charms}. See Deuteronomy. 18:10-12 and Isaiah 47:9.

Modern History
In AD 800's the Pope in an effort to "Christianize" the pagan holiday started a mass to be said for all the martyred saints. This was called "All Souls Day" and was held on the first of November. The night before was called All hallow's Eve, then All hallow E'en, and finally Halloween. Even now the pagan practices didn't stop they simply took on a new form. The bones of the saints were holy and if you paid great amounts of money you could touch them and maybe be healed. Then they started selling other fake relics, and eventually Indulgences. If You bought an Indulgence you could go out and sin, because it was paid for in advance so if you died you would still go to heaven. All these things would take place on Halloween. This twisted mixture of Christianity and Paganism so outraged one godly man, that he vowed he would change it or die trying. On the Halloween of 1517 Martin Luther nailed the 95 theses to the door of the Wittenburg church to protest these and other things. This marked the date of the Protestant Reformation.
Witchcraft is not dead. In England, at the ancient ruins of Stonehenge, Druid priests perform ancient rites, as their ancestors did. The sacrificing of animals and, occasionally, people was still not uncommon. Even in our time, animals are sacrificed on Halloween in Europe and in the Philippines, as well as in the USA.
In the USA Halloween did not become popular until the mid 1800's when large groups of the Irish and Scottish immigrated and introduced their specific customs of celebrating Halloween.
Since 1965 with the publishing of the Satanic bible and 1969 with the first church of Satan and the revival of old Celtic style witchcraft in Missouri and North Carolina, Satanism and Witchcraft has been on the rise.
Witchcraft and sorcery are very real. The number of occult-related murders has been on the increase in this country for more than a generation. One of the most celebrated occult dates is Halloween, and is celebrated in this country on October 31. On college campuses and universities today, Anton LaVey's Satanic Bible often out sells the Bible itself.

Paul's point
Paul wrote his epistle to the Galatians, who were Celts that settled in a small region of what is now modern day Turkey. He was so shocked that the Celtic Christians were going back and observing their old pagan holidays that he says:

Galatians 4:8-11 However at that time, when you did not know God, you were slaves to those which by nature are no gods. ⁹ But now that you have come to know God, or rather come to be known by God, how is it that you turn back again to the weak and worthless elemental things, to which you desire to be enslaved all over again? ¹⁰ You observe days and months and seasons and years. ¹¹ I fear for you, that perhaps I have labored over you in vain. (NASB)

If Paul was so shocked at the celebration of Halloween that he didn't know if they were truly Christian, should we be practicing it?

For more information on the medieval rites, practices and history of Halloween, see the Encyclopedia Britannica; Man, Myth, and Magic, a 24 vol. Encyclopedia; The Larousse Encyclopedia of Mythology and many other books and encyclopedias in your local library.

Rev 2