Virgin of the Immaculate Conception with Saints Andrew and John the Baptist by Juan de Valdes y Leal 1650
Feast: December 8th
We declare, pronounce and define that the doctrine which holds that the Blessed Virgin Mary, at the first instant of her conception, by a singular privilege and grace of the Omnipotent God, in virtue of the merits of Jesus Christ, the Saviour of mankind, was preserved immaculate from all stain of original sin, has been revealed by God, and therefore should firmly and constantly be believed by all the faithful.
—Pope Paul IX, Ineffabilis Deus, December 8, 1854
