The Origin of Christmas
Christmas Day-December 25-which celebrates the birth of Jesus Christ， the founder of the Christian religion， is the biggest and best-loved holiday in the United States.
According to the Bible， the holy book of Christians， God decided to allow his only son， Jesus Christ， to be born to a human mother and live on earth so that people could understand God better and learn to love God and each other more. "Christmas"- meaning "celebration of Christ "- honors the time when Jesus was born to a young Jewish woman Mary.
Mary was engaged to be married to Joseph， a carpenter， but before they came together， she was found to be with child. Because Joseph， her husband， was a righteous man and did not want to expose her to public disgrace， he had in mind to divorce her quietly. But after he had considered this， an angel of the Lord appeared to him in a dream and said， "Do not be afraid to take Mary home as your wife， because what is conceived in her is from the Holy Spirit. She will give birth to a son， and you are to give him the name Jesus， because he will save his people from their sins."
Although the exact date of the birth of Jesus nearly 2，000 years ago is not known， the calendar on the supposed date divides all time into B.C. (Before Christ )and A.D. ( a Latin phrase， Anno Domini， "in the year of our Lord.")For the first 300 years， Jesus’ birthday was celebrated on different dates. Finally， in the year 354， church leaders chose December 25 as his birthday.
聖誕節只是基督徒慶祝其信仰的耶穌基督(jīdū)誕生的慶祝日。聖誕節的慶祝與基督教同時產生，被推測始於西元1世紀。很長時間以來聖誕節的日期都是沒有確定的，因為耶穌確切的出生日期是存在爭議的，除了《新約》以外，沒有任何記載提到過耶穌;《新約》不知道日期，當然就沒有人知道確切日期了。在西元後的頭三百年間，耶穌的生日是在不同的日子慶祝的。西元3世紀以前的作家們想把聖誕日定在春分日上下。直到西元3世紀中期，基督教在羅馬合法化以後，西元354年羅馬主教指定儒略曆12月25日為耶穌誕生日。現在的聖誕節日期跟西元紀年的創製是密不可分的。
西元紀年創製於西元5世紀，後來聖誕節這一天就按格里高利曆法，即西元紀年的“公曆”來確定了，而日曆按著假定日期把時間分為公元前(耶穌基督誕生前)和公元後(A. D. 是拉丁文縮寫，意思是“有了我們主--耶穌的年代”)。後來，雖然普遍教會都接受12月25日為聖誕節，但又因各地教會使用的曆書不同，具體日期不能統一，