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 p>

　　Although the exact date of the birth of Jesus nearly 2，000 years ago is not known， the calendar on the supposed date p>

　　圣誕節只是基督徒慶祝其信仰的耶穌基督(jīdū)誕生的慶祝日。圣誕節的慶祝與基督教同時產生，被推測始于西元1世紀。很長時間以來圣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。在西元后的頭三百年間，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圣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后，西元354年羅馬主教指定儒略歷12月25日為耶穌誕生日。現在的圣誕節日期跟西元紀年的創制是密不可分的。

　　西元紀年創制于西元5世紀，后來圣誕節這一天就按格里高利歷法，即西元紀年的“公歷”來確定了，而日歷按著假定日期把時間分為公元前(耶穌基督誕生前)和公元后(A. D. 是拉丁文縮寫，意思是“有了我們主--耶穌的年代”)。后來，雖然普遍教會都接受12月25日為圣誕節，但又因各地教會使用的歷書不同，具體日期不能統一，