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>
圣诞节只是基督徒庆祝其信仰的耶稣基督(jīdū)诞生的庆祝日。圣诞节的庆祝与基督教同时产生，被推测始于西元1世纪。很长时间以来圣诞节的日期都是没有确定的，因为耶稣确切的出生日期是存在争议的，除了《新约》以外，没有任何记载提到过耶稣;《新约》不知道日期，当然就没有人知道确切日期了。在西元后的头三百年间，耶稣的生日是在不同的日子庆祝的。西元3世纪以前的作家们想把圣诞日定在春分日上下。直到西元3世纪中期，基督教在罗马合法化以后，西元354年罗马主教指定儒略历12月25日为耶稣诞生日。现在的圣诞节日期跟西元纪年的创制是密不可分的。
西元纪年创制于西元5世纪，后来圣诞节这一天就按格里高利历法，即西元纪年的“公历”来确定了，而日历按着假定日期把时间分为公元前(耶稣基督诞生前)和公元后(A. D. 是拉丁文缩写，意思是“有了我们主--耶稣的年代”)。后来，虽然普遍教会都接受12月25日为圣诞节，但又因各地教会使用的历书不同，具体日期不能统一，