In its symbolism, the Church continues to stress the penitential and preparatory nature of Advent. Purple vestments are used, and the Gloria is omitted during Mass.
The only exception is on the Third Sunday of Advent, known as Gaudete Sunday, when rose-colored vestments can be used. This exception is designed to encourage us to continue our prayer and fasting, because we can see that Advent is more than halfway over.
Perhaps the best-known of all Advent symbols is the Advent wreath, a custom which originated in Germany. Consisting of four candles (three purple and one pink) arranged in a circle with evergreen boughs (and often a fifth, white candle in the center), the Advent wreath corresponds to the four Sundays of Advent.
The circle of the wreath, which has no beginning or end, symbolizes the eternity of God, the immortality of the soul, and the everlasting life found in Christ. The purple candles represent the penitential nature of the season, while the pink candle calls to mind the respite of Gaudete Sunday.
The white candle, when used, represents Christmas. The candle flames signify Christ, the Light of the world. (9:3)