Because the Blessed Mother was originally conceived without sin, the angel Gabriel referred to her as being "full of Grace." Thinking back on the mystery of Mary's immaculate conception might serve as a reminder of the atoning work Jesus came to accomplish through His Incarnation, as the Church gets ready for the arrival of Christ on Christmas Day.
Major Feast: The Solemnity of the Immaculate Conception - December 8 Celebration Ideas: Go to confession. This is a wonderful way to get ready for Christmas and will grant you the ability to emulate Mary's virtues.