The following comes from the CNA:
The Church's nature and destiny are revealed in the Virgin Mary's perfect holiness, Pope Benedict XVI taught on the Dec. 8 Feast of the Immaculate Conception.
“In her sinless perfection, Mary is a great sign of hope for the Church and for the world, a sign of the marvels that God's grace can accomplish in us, his human creatures,” the Pope said in his remarks at the midday Angelus in St. Peter's Square.
Christ's mother, he explained, received the fullest possible measure of the same grace given to believers through the sacraments of the Church.
“The expression 'full of grace' indicates the marvelous work of God, who wanted to give us back the life and liberty, lost by sin, through his only begotten Son,” said the Pope, reflecting on the Archangel Gabriel's greeting to Mary.
“We too are given the 'fullness of grace' that we need to shine in our lives,” he pointed out, citing Saint Paul's teaching that God “has blessed us with every spiritual blessing” and “destined us to be (his) sons” through baptism.
The Pope explained that Mary's complete preservation from original sin – a perennial teaching of the Church, formally proclaimed by Blessed Pope Pius IX in 1854 – was a “special grace and privilege of almighty God,” given to her “in anticipation of the merits of Jesus Christ.”
By this privilege, she became a prototype of the Church – which is “the virgin mother of all Christians,” in the words of St. Hildegard of Bingen cited by the Pope.
The same Pope who formally defined the Immaculate Conception, also confirmed Mary as the patroness of the United States under that title in 1847.
After leading the crowd in prayer, Pope Benedict offered his special greetings to English-speaking pilgrims on the feast day.
“In these days of Advent, in company with the holy and immaculate Mother of God,” he said, “let us prepare to welcome her son into our lives and into our hearts.”
“May God bestow His blessings of joy and peace upon all of you, and upon your families and loved ones at home.”