My host mother said that long time ago, everybody will provide food to poor and beggar on Halloween. But poor and beggar become naughty, they make up like ghost to scare people and ask more food. So, that’s why children”trick or treat?” now.
I asked the same question to my classmates, most of them said” We just celebrate and have fun. I don’t now” Than, I asked English teacher, he said Halloween is All Saints Day‘s eve (Nov. 1 is All Saints Day). I got 2 different answers, so I decided to check on internet.
A lot of different opinions about Halloween hereinafter are some of them. Which one is truth? It’s up to you!
傳說中最早的萬聖節，可就帶點陰森森的氣氛哦！十一月一日是所謂的『萬聖節』 (All Saints Day)。西元前五世紀愛爾蘭的凱爾特人，他們 的新年是在每年夏季結束的時候，就是十月三十一日那天。凱爾特人認為在新舊年交接時刻的夜晚，也就是十月三十一日的夜晚，看不見的靈 魂會在陽世中穿梭，找到替身後得以重生；因此活著的人為了躲避靈魂的搜索，就在這天晚上把家裡的爐火滅了，營造出一個寒冷陰森的環境 ，並且打扮成鬼怪的模樣，口中發出可怕的聲音，企圖嚇走靈魂也讓靈魂分不清誰是活人，因而不能夠找到替身；只要過了這個晚上，第二天 就是萬聖節，一切也就回復平靜了。
萬聖節的裝飾多以橘色和黑色為主，這兩個顏色也是傳統的萬聖節裝飾代表顏色。黑色的代表像是黑貓、蜘蛛和巫婆，和橘色的代表南瓜燈 (Jack-O’-Lantern) ，都是常見的萬聖節象徵，除此之外還有各式面目猙獰的鬼怪和骷髏等等。
--Adopt from 新竹關東國小(http://www.ktps.hc.edu.tw/ghost/index.html)
到了第四世紀，因為基督教興盛，這一天改為上帝死亡日，相信上帝會趕走惡靈。後來，演變成小孩穿上鬼和精靈的衣服，按鄰居家的門鈴， 依傳統發出「Trick or Treat」的威脅，鄰居們不管是否被嚇著，總是會為孩子準備糖果、餅乾、焦糖蘋果等點心，讓孩子滿足的將戰利品收 入袋內離去。
It all began in what is now France and the British Isles. It was started by the Celtic people long ago....
The Celtic people feared the night of October 31. It was the night of their festival of Samhain, Lord of the Dead. The Celtics feared Samhain and in order to please him, the Druids (Celtic priests) held cruel fire rites in his honor. They made huge bonfires every year at this time. The bonfires were usually made of oak and considered sacred.
At this festival, the Druids made sacrifices to the gods. They burned criminals, prisoners, and animals alive. By observing the victims die, the Druids saw omens of the future, both good and bad. The powers to make predictions of the future were thought to be strongest on this night. Why? It was because the Druids believed that the spirits were allowed to roam free on this night of the year. The Druids believed the spirits were powerful and wild on this night, and if they were treated right, they would help with predictions of the future. However, if the spirits were ignored, they would punish the Celtic community.
The Druids believed that, above powerful and wild, some spirits were evil. This is why the Celtic people wore costumes during the Samhain festival. The purpose of the costumes was to frighten the spirits. Plus, this way, the spirits wouldn't be able to recognize them.
(This is the origin of costumes.)
To please the spirits, the Celtic people left food outside their houses on Halloween. If any hungry spirits came by, they could take the food and leave the Celtics in peace.
(This is the origin of 'trick or treat'ing.)
This web site have a lot detils about Halloween. I think it's worth to visit! It's History Channel! http://www.historychannel.com/exhibits/halloween/