We honor Mary, our Mother. The Solemnity of the Immaculate Conception is a feast day celebrating Mary’s conception without sin. The dogma of the Immaculate Conception asserts that, “from the first moment of her conception, the Blessed Virgin Mary was, by the singular grace and privilege of Almighty God, and in view of the merits of Jesus Christ, Savior of Mankind, kept free from all stain of original sin.”