MARY the mother of God is venerated on December 8th as the Immaculate Conception. This feast commemorates the preservation of the Blessed Virgin from the stain of original sin from the first moment of her conception. It originated in the Eastern Church about the 8th century.
The doctrine of the Immaculate Conception was defined by Pope Pius IX on December 8, 1854. This dogma is in accord with the texts of Scripture: “I will put enmity between you and the woman, between your seed and her seed” (Gn 3, 15), “Hail, full of grace” (Luke 1, 28), and was clearly understood and accepted by tradition, by the writings of the Fathers and by feasts to the general belief of the faithful long before it was defined by Pope Pius IX.