Advent originated as a time of preparation for candidates for church membership prior to their baptism on Epiphany, January 6. Between the fourth and seventh centuries, the season varied from three to as many as seven weeks in different parts of Christendom. During this time, Advent came to be seen as a time of preparation for all believers in anticipation of Christmas. The Roman church set the season's length at four Sundays in the sixth century, and in the eleventh century Gregory VII decreed that this would be the standard for the whole church. In the late Middle Ages, penitence was added to the emphasis on preparation.
Advent is above all a time of joyful anticipation.
It is, therefore, a time when the church looks back at the historical event of Christ's nativity, looks around at the revelation of Christ in scripture and experience, and looks ahead to Christ's return at the end of time. It is still thought of as a time of personal introspection and preparation. During Advent, emphasis is placed on the reading of Old Testament prophecies of the coming of the Messiah. The lighting of an Advent wreath is a familiar custom during this season in churches and in homes. A wreath is formed, usually of evergreen branches, and adorned with four purple or blue candles.