Catechism of the Catholic Church

To become the mother of the Savior, Mary "was enriched by God with gifts appropriate to such a role." The angel Gabriel at the moment of the annunciation salutes her as "full of grace." In fact, in order for Mary to be able to give the free assent of her faith to the announcement of her vocation, it was necessary that she be wholly borne by God's grace. (2676, 2853, 2001)