Mary is a pillar of the Church because of her faith

"Blessed are you who believed!" (Lk 1:45) If beatitude is an act in conformity with the perfect virtue of the soul, Mary was extremely blessed because she was completely filled with virtue and grace; she was prudent and full of faith, to the point of deserving to conceive because of her faith, and to become the foundation and pillar of the Church thanks to her faith.

To believe means, as St Augustine says, to give the consent of one's own mind and to adhere with complete devotion to what one believes. In offering her assent, Mary said, "Let it be done to me according to your word" (Lk 1:28).

Reflecting, she asked about the way it would happen; but with piety, she sought in whom she should believe when, praying, she drew the Word to herself, repeating in spirit the Song: "My beloved belongs to me and I to him" (Ct 2, 16), and also: "leaning upon my beloved" (Ct 8, 5).

Faith is a light that brings the truth to those who believe.

Through knowledge, Mary was placed in the truth and the truth, with the Incarnation, was placed into her.

Saint Albert the Great, In Lucam 1, 45

See also: Marian Encyclopedia