Halloween has origins in Celtic and pagan rituals when people believed that Samhain (the Celtic name for Halloween, pronounced 'sow-ain') was a time when the veil between this world and the next was thinnest; therefore, communication and contact with spirits or the spiritual realm was strongest.
Rosemary Guiley states that Samhain "celebrates the beginning of winter, marked by death, and the beginning of the Celtic New Year.....(....)....Samhain is a time for taking inventory of life and getting rid of weaknesses and what is no longer desired," [__The Encyclopedia of Witches & Witchcraft__, 2nd ed., (NY, NY: Checkmark Books/Facts on File, p. 356)].
Halloween is one of the eight sacred or special days of celebration for many in the Pagan community. However, there is no evidence that any group uses this day as a day of sacrificing animals or people, and Christians therefore should not assume this nor believe wild stories about such practices, nor should Christians spread such stories. Christians need to remember the commandment about not bearing false witness. Pagan holidays are connected to the Pagans' reverence for nature and the seasonal changes; sometimes these beliefs incorporate and celebrate the stories of various pagan gods. And no matter what beliefs people hold, as Christians we are called on to respect all people because all men have been created in the image of God.
Christians should not buy into rumors that witches or Satanists are killing people or sacrificing them on this day. Christians should consider Halloween a good day to pray for those in the occult, that they would come to know the love and grace of Christ, and the forgiveness of sins through trusting Christ as the Savior who shed His blood on the cross for them. This is the message they need to hear in love.
As for trick-or-treating, that is up to the individual parent. Certainly, one hopes that Christians would not let their child dress up as a witch, demon, devil, ghost, or other figure that belongs to the world of death or the occult.
Churches can offer alternative celebrations, such as a harvest day, and invite the area children to come play games, have treats, and hear Bible stories.
Since Halloween is my birthday, I have a special concern for this day. It is ever a personal reminder to me of the passage of time, and a reminder of those in the occult who embrace darkness and need the Light of Christ.
Jesus read in the Temple these words from Isaiah 61: "'The Spirit of the Lord is on me, because he has anointed me to preach good news to the poor, He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to release the oppressed, to proclaim the year of the Lord's favor.' Then he rolled up the scroll, gave it back to the attendant and sat down. The eyes of everyone in the synagogue were fastened on him, and he began by saying to them, 'Today this scripture is fulfilled in your hearing.'" (Luke 4:18-21; Jesus was the fulfillment of Isaiah's prophecy).
"For he has rescued us from the dominion of darkness and brought us into the Kingdom of the Son he loves, in whom we have redemption, the forgiveness of sins." (Colossians 1:13-14).
ADDED THOUGHTS FROM 2014:
HALLOWEEN IN THE U.S. IS LIKELY A CONVERGENCE OF BOTH PAGAN AND MIXED CHRISTIAN ORIGINS, but what really matters is how Halloween is viewed in the culture today and how it is observed. Aside from the All Saints Day (Nov. 1) and the evening before (All Hallow's Eve) from which we get "Halloween," there is still a Celtic legacy brought over mostly by Irish immigrants, and an older pagan seasonal holiday, Samhain.
Frankly, the supposed Christian origin of honoring the dead (or "saints") does not strike me as very biblical. I see no reference for this in the Bible and I have no desire to "honor" dead people. I can miss them and maybe respect what they have done, but I don't think in terms of "honoring" dead people.
Halloween is a special day for those in Neopagan religions such as Wicca and Witchcraft, and is also observed by some Satanist groups .However, this does not make the day itself evil (so no need to fear Halloween or hide on Oct. 31). A day cannot be evil.
KEEP IN MIND that there are different accounts of the origins of Halloween, and scant historical verification for much of what you may read. Again, origins do not matter as much as how it is celebrated now.
And what matters even more is the ongoing promotion throughout the year of the occult in books, movies, TV shows, and video games. So why focus so much on one day?
Here is some information from an article by folklorist Jack Santino:
Excerpt==Halloween is a quintessentially American holiday.
Traditions focused on accumulation and consumption may seem very American, and certainly an American-style Halloween has evolved. But the origins of the holiday can be traced back to a pre-Christian Celtic festival called Samhain (pronounced "SAH-wen"). For the Celts, Nov. 1 marked the end of the harvest and the beginning of the new year. They believed that the souls of the dead mingled among the living at that time. And so they associated the fruits of the harvest with death, the afterlife and the supernatural.
Later, after Saint Patrick and other missionaries converted Ireland to Christianity, Nov. 1 became All Saints' Day, or All Hallows Day, and the eve of All Hallows became known as Halloween. It featured feasts, the blessing of the hearth, and the lighting of candles and bonfires to welcome wandering souls. It was and remains a family celebration in Ireland.
Few early American settlers observed Halloween. It was Irish immigrants in the 19th century who were responsible for bringing many Halloween customs to the United States.
...Actually, the devil wasn't part of the Samhain festival celebrated by the Celts -- or the druids, who made up their priestly caste. They made sacrifices in honor of the dead, but those sacrifices more often took the form of burned crops rather than animals. Contrary to some accounts, there was no human sacrifice.
...Beliefs in the wandering dead persisted, but the supernatural beings honored by the Celts became associated with evil. And the Celtic underworld became associated with the Christian hell. Yes, devils remain a symbol of Halloween -- and you may see a few of them scurrying from door to door.
...Wearing costumes and demanding treats can also be traced to the Celtic period and the first few centuries of the Christian era, when food and drink were left out to placate wandering souls, fairies, witches and demons. As the centuries wore on, people began dressing like these creatures, performing antics in exchange for food and drink. By the Middle Ages, masked solicitations were associated with All Souls' Day and other holidays in countries influenced by Catholicism.
according to folklorist Tad Tuleja, trick-or-treating did not descend
directly from those traditions. By his account, the practice as we know
it in the United States is largely a product of an effort by local
governments and businesses in the 1930s and '40s to promote an
alternative to pranking and the rowdier aspects of Halloween. "Trick or
treat has gradually replacedbuggy stealing as the 'appropriate' way for
children to enjoy the holiday," he writes.
Indeed, early descriptions of Halloween in the United States generally don't reference any activities that resemble knocking on doors to ask for treats. The practice became ubiquitous, however, in the post-World War II years, after the lifting of sugar rations and as suburbanization made going from house to house easier than when people lived far from their neighbors.==End excerpt