With the Christian holiday established, people wanted to be prepared for the upcoming celebrations. Advent, taken from the latin adventus ("coming") is now the four week period prior to Christmas Day observed by many Christmas throughout the world. It is a time which believers are to undergo a spiritual cleansing and sometimes ritual fasting in preparation for the feast of Nativity, or Christmas.
Although legend holds that advent was attribited to the Apostle Peter, the exact date of its inception is not precisely known. There are writings vaguely referring to advent ranging from the fourth to sixth centuries. Pope St. Gregory the Great (590-604) only included a sermon on the second Sunday of Advent, and in 650 Advent was expanded to five Sundays before Christmas. This was changed again to four Sundays by Pope St. Gregory VII in the eleventh century.
Advent focuses on the four great comings of Christ: His coming of the flesh, His coming into the hearts of believers, His coming at the hour of death, and His coming at the final judgement. In some traditions there are four colours associated with the Advent season: dark blue, purple, rose or pink, and light blue. Also, candles representing each Sunday of Advent are lit, one per Sunday up to Christmas Day. On Christmas Day a large red candle is added, representing Christ.
One variation is to light one candle with the numbers one through twenty-five stamped on the side. The candle is lit on December 1 and allowed to burn down to the next number. It is then extinguished and relit the next day. This is the precusor to the advent calendar for children. Traditionally, the advent calendar had little flaps, each one contained a bible verse for the child to read to remind him or her of piety and obediance. Now, a child can find a small toy, candy, or money in the calendar.
Whatever your tradition, Advent marks the beginning of the Christmas season for Christians, heralding the coming of Christ. It is filled with anticipation and preparation. Use the season to personally reflect on what makes Christmas special to you. Then on Christmas Day you can celebrate!
Source: The Christmas Encyclopedia by William D. Crump