The Immaculate Conception of the Blessed Virgin Mary
Having decided from all eternity to make Mary Mother of the Incarnate Word, God willed that she should crush the head of the serpent from the moment of her conception. He covered her with a mantle of holiness and made her soul which He preserved from all stain, a worthy dwelling place for His Son. On December 8, 1854, Pope Pius IX officially proclaimed the Dogma of the Immaculate Conception.
Thou art all fair, O Mary: and the original stain is not in thee. Thy vesture is white as snow; and thy face is as the sun. — First Vespers, Antiphon
The Imitation of Christ
O happy mind and blessed soul! which deserveth to receive Thee, her Lord God devoutly, and in receiving Thee to be filled with spiritual joy.
This is our Mother's greatest feast. And, oh, are you not proud of your Mother? Of course, you can never really appreciate the fact that our Lord gave her to you, His Mother to you. And today, while the angels surround her with songs of praise for her, their Queen, they are honoring your Mother, Queen of the Angels, but your Mother.
It is hard to say words today; all one can do, is to keep from shouting for sheer exultation and happiness at the glory that heaven and earth shower on your Mother, knowing all the while that amidst the clouds of incense from angels’ censers, amidst the songs of saints and angels, your Mother thinks of you, waits with love for your mite of praise.
Hail Mary, full of grace, the Lord is with thee.