From today’s entry in the Roman Catholic Daily Missal:
“I will put enmities between thee and the woman.” In these words the Immaculate Conception of the Blessed Virgin Mary was announced to our first parents. It was to be the reversal of the friendship with the serpent contracted by Eve, when she listened to his voice and fell under his power. The second Eve was never to be under the power of the devil; the enmity between them was to admit of no possible exception. This involved the grace of being conceived immaculate. Mary’s Immaculate Conception was the foundation of all her graces. The absence of any stain or spot of sin distinguished her from all the rest of mankind. It distinguished her from the holiest of the saints, since they, one and all, were sinners. Her perfect sinlessness was the source of all her glory and all her majesty; it was this which opened the door to the unlimited graces that she received from God; it was this that qualified her for divine maternity, and raised her to her throne as Queen of heaven.
“O Queen, conceived without original sin, pray for us, who have recourse to thee.”