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Creed › … › Paragraph 2. "Conceived by the Power of the Holy Spirit and Born of the Virgin Mary"
The Immaculate Conception
Through the centuries the Church has become ever more aware that Mary, "full of grace" through God, was redeemed from the moment of her conception. That is what the dogma of the Immaculate Conception confesses, as Pope Pius IX proclaimed in 1854:
The most Blessed Virgin Mary was, from the first moment of her conception, by a singular grace and privilege of almighty God and by virtue of the merits of Jesus Christ, Saviour of the human race, preserved immune from all stain of original sin.
Source: Catechism of the Catholic Church (Vatican.va)