Feast of the Nativity of Mary

Today we Catholics celebrate the Immaculate Conception of Mary Mother of God. On Our Lady's birthday the Church celebrates the first dawning of redemption with the appearance in the world of the Savior's mother, Mary. The Blessed Virgin occupies a unique place in the history of salvation, and she has the highest mission ever commended to any creature. Mary was born to be the mother of the Savior of the world, the spiritual mother of all men, and the holiest of God's creatures. Because of her Son's infinite merits, she was conceived and born immaculate and full of grace. Through her, Queen of heaven and of earth, all grace is given to men. Through her, by the will of the Trinity, the unbelieving receive the gift of faith; the afflicted are tendered the works of mercy; and the members of Christ grow in likeness of their Head. In Mary all human nature is exalted. We rejoice in her birthday, as the Church has done from the earliest times. This is one of the three birthdays in the Church Calendar — the Birth of Jesus (December 25), the Birth of John the Baptist (June 24) and the Birthday of Mary. All three were born without original sin, although Mary and Jesus were conceived without sin, and St. John was cleansed of original sin while in the womb at the Visitation of Mary.

(taken from Catholic Culture)