In the Constitution Ineffabilis Deus of 8 December, 1854, Bl. Pope Pius IX pronounced and defined that the Blessed Virgin Mary "in the first instance of her conception, by a singular privilege and grace granted by God, in view of the merits of Jesus Christ, the Saviour of the human race, was preserved exempt from all stain of original sin."
It was Mary who was conceived immaculately. The birth of Christ, meanwhile, is the Virgin Birth: his mother Mary was a virgin when she gave birth to him, her virginity remained intact during His birth, and she retained her virginity her entire life.
Original sin is a moral deformity, a permanent privation, a wound in our human nature, transmitted like a birth defect from our first parents, Adam and Eve: it is the chief consequence of their deliberate disobedience of God in the Garden of Paradise.
Its effects include:
* Suffering and death. These are physical evils rather than moral evils.
* The rebellion of the lower appetites over the higher faculties. This is called concupiscence, and it's why we have a desire for forbidden things and a fascination for evil. It's also why we find it easy to do what's wrong and difficult to do what's right. We still have free will; we also still know moral truths with certainty, but with difficulty. Concupiscence is not a moral shortcoming in and of itself; rather, it is the weakness of the intellect and the will that inclines us to fail morally.
* The absence of sanctifying grace at birth. This means we don't have the intimate union with God that we need to be truly happy throughout our lives, both in this world and in the world to come. Baptism restores this grace, which is why it is necessary for salvation.
By being immaculately conceived, the Blessed Virgin Mary always enjoyed sanctifying grace and never suffered concupiscence: her mind was always clear, her will was always under control, and she used both her entire life to love, honor, and serve Almighty God, Deo gratias.
"Would you be so kind as to tell me who you are?" Bernadette asked the beautiful woman -- four times in fact.
"I am the Immaculate Conception," was the reply -- or, rendered in the local dialect, "que soy era Immaculada Councepciou."
Bernadette gave the reply to her pastor. He was astonished. "You are mistaken," he said. "Do you know what that means?"
The little girl did not: the title that the Pope had declared for the Mother of God had been solemnly declared only four years before, and news of the matter was still being discussed primarily among theologians and clergy. Further, Bernadette was illiterate, and she was conversant only in the Bigourdan patois of the region. Because of her family's poverty and her own ill health, she was six years tardy in preparing for first Holy Communion. It was too incredible that she would know the term "Immaculada Councepciou."
But Bernadette was correct, and her pastor finally overcame his surprise to support her to the local bishop.
Our Lady, meanwhile, went about petitioning her Son in Heaven on behalf of those who came to honor Her as the Immaculate Conception, and the thousands of miraculous cures and other miracles at the shrine in Lourdes give testimony that it pleased God in Heaven that His mother should be so honored.
Immaculada Councepciou, ora pro nobis.