How is it that the Virgin Mary was able to understand without discernment that it really was the Archangel Gabriel appeared to her?
Mary had the following to her advantage during the Annunciation:
- Mary was as the Angel Gabriel stated “Full of Grace”.
- She was the unspeakably overshadowed by the Holy Spirit (Luke 1:35).
- Mary was able to give the free assent of her faith by graces given to her by God.
- Mary was docile to God’s will.
- The Holy Spirit constantly guided and inspired the Holy Virgin Mary.
At her Annunciation the angel sent from Heaven greets Mary, not by her name, but by a title, saying, “Hail, Full of Grace.” [The Greek word used by Luke here], “kecharitomene, indicates that God has already graced Mary previous to this point, making her a vessel who ‘has been’ and ‘is now’ filled with divine life” (Ignatius Catholic Study Bible). As the Catechism of the Catholic Church states, “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” (no. 490). The sanctifying indwelling of the Holy Spirit was uniquely present to Mary Immaculate from the first moment of her life!
And then during her Annunciation, probably while she was only a teenager, and after having given her consent, the “unspeakable” shadow of the Holy Spirit overshadowed Mary (Luke 1:45), and she became so possessed by the Holy Spirit, so fully divinized by His union with her, that a child, a Divine child, was conceived within her womb.
Saint Luke then shows us that Mary is fully alive in the power of the Holy Spirit, for when Mary visits her cousin Elizabeth there is a veritable explosion of Holy Spirit power at the very sound of Mary’s voice! (see Luke 1:39-56). Everything in Mary’s life is taking place under the guidance and power of the Holy Spirit! - The Holy Virgin Mary was Completely Docile to the Holy Spirit
Mary having been Immaculately Conceived by a singular privilege by God made it that She lived her life in an extremely high level of union with God and thus revived graces necessary to her station.
Defined by Pope Pius IX in Ineffabilis Deus, 1854, it states that Mary, through God's grace, was conceived free from the stain of original sin through her role as the Mother of God:
We declare, pronounce, and define that the doctrine which holds that the most Blessed Virgin Mary, in the first instance of her conception, by a singular grace and privilege granted by Almighty God, in view of the merits of Jesus Christ, the Saviour of the human race, was preserved free from all stain of original sin, is a doctrine revealed by God and therefore to be believed firmly and constantly by all the faithful.