From the Annunciation to the Cross, Mary always assented with the same obedience of faith to all revelation, to all the designs of God. Every moment of Her life was an invitation to act on Her faith, and as a fruit of Her obedience, She in turn, deepened Her faith and understanding of Her role and participation in the plan of salvation. That is why we can truly say that Mary had a pilgrimage of faith from the Annunciation to Her Assumption, and that this pilgrimage climaxed on Calvary.
At the moment of the Annunciation, Mary was presented with two different and amazing revelations: first, that She was full of grace, and second, that She was being chosen to receive the greatest invitation a creature had ever received – to become the virgin mother of the Messiah, the Son of God. This conception was to be accomplished by the overshadowing of the Holy Spirit, a miracle! Something impossible for men but not for God. It was precisely this human impossibility and this divine possibility that called Mary to open Herself totally to the gift of faith – and She believed in Her God, a God that could do that kind of miracle, a God that chose His lowliest servant for such a dignified and exalted vocation and mission.
St. Augustine said that “Mary first conceived in her heart by faith and then in Her womb” (cf. Sermon 293). Mary’s response, “may it be done to me according to your word” (Luke 1:38), is a sign of Her full assent to the will of God, to the revelation received, to Her role in this redemptive mission. Only a heart full of faith like Mary’s can give that kind of assent to such a vocation and to all the unexpected events that would form that reality – a series of events that were far beyond human intelligence or human calculations.
From that moment, faith became for Mary the only pillar on which to sustain Her whole life and the only way to embrace, not only Her own mystery, but the mystery of Her Son: a gift of mercy from God the Father for the salvation of all humanity. All other events in Mary’s life could only be comprehended in the light of faith, a faith that allowed Her to perceive the hidden sense of things and situations and helped Her discover in all things the provident will of God, His presence and His mysterious designs.
Many times the external appearances of situations could have seemed enough to prove false Her faith. It was precisely at these moments when Mary “kept all things in her heart” (Luke 2:51), allowing the Holy Spirit to enlighten, to strengthen and to deepen Her faith. This reverent act of Mary of keeping all things in Her heart, especially those She did not fully understand, was an honest search for the hidden sense of the events that She knew by faith must exist, since the Lord could have never abandoned or misled Her.
The Dogmatic Constitution on the Church, Lumen Gentium, presents Mary on a journey, on an itinerary of faith, that was manifested in all the different stages She lived during Her earthly life: “Embracing God’s salvific will with a full heart and impeded by no sin, She devoted Herself totally as a handmaid of the Lord to the person and work of Her Son, under Him and with Him, by the grace of almighty God, serving the mystery of Redemption.... freely cooperating in the work of human salvation through faith and obedience” (no.56).
Mary’s faith did not only sustain Her life, but it gave abundant fruit for our redemption since, as Lumen Gentium describes, by Her faith, Mary freely and fully cooperated in the work of human salvation. “For, as St. Irenaeus says, She ‘being obedient, became the cause of salvation for herself and for the whole human race…The knot of Eve's disobedience was untied by Mary’s obedience; what the virgin Eve bound through Her unbelief, the Virgin Mary loosened by her faith’” (ibid).
Mary at the Foot of the Cross
“Standing by the foot of the Cross of Jesus were his mother and his mother’s sister, Mary the wife of Clopas, and Mary of Magdala. When Jesus saw his mother and the disciple there whom he loved, he said to his mother: ‘Woman, behold your son.’ Then he said to his disciple, ‘Behold your mother.’ And from that hour the disciple took her into his home” (Jn 19:25).
I believe that St. John, in this passage, wants to exalt Mary’s faith by presenting two elements in reference to this event:

First, Mary’s presence at the foot of the Cross. It is precisely at this place where the faith of the disciples and, logically, Mary’s faith, is put to the hardest test. Her presence manifests Her fidelity, Her constant abandonment to the designs of the Lord’s will, and a faith that is undiminished, unchanged and unaltered even in the darkest hours.

Second, in the words of Jesus, “Behold your son,” Mary is invited to expand the horizon of Her faith and the understanding of Her role, since Her motherhood is now moving beyond Her dying son; it is been extended to the reality of a spiritual maternity for all the children of God. This last will of Jesus on the Cross became, for Mary, a new annunciation of a conception and birth: The Church.
Mary’s faith was constant, not only present in the times of “apparent glory” when Her Son was performing miracles and had many disciples that believed in Him; it was just as strong when there was no “apparent glory,” when there were no supernatural manifestations or happenings to attract attention, and even when there were not that many disciples to believe – except one, the one that was with Her at the foot of the Cross.
The same faith that Mary had at the birth of Her Son was the one She had at the Cross. It required much faith to have in Her arms that defenseless baby, and to put him in the manger and believe that He was the God-man. It also required much faith to see Her Son totally disfigured and defenseless on the Cross, waiting for him to be placed in Her arms, to then be put in the sepulcher. Her faith allowed Her to continue to believe that, regardless of what appeared to be, He was the God-man.
In Cana Jesus proclaimed that it was not his “hour,” and Mary’s faith and intercession, manifested in the form of a petition, achieved the first miracle, the miracle of the wine. At the Cross, when it was in fact Jesus’ Hour, Mary’s faith and intercession, now manifested in silence, also witnessed the outpouring of the new wine, the blood of Her Son being shed for our salvation, to quench our thirst for God and His divine life.
“The Blessed Virgin advanced in her pilgrimage of faith, and faithfully persevered in her union with her Son unto the Cross, where she stood, in keeping with the divine plan, grieving exceedingly with her only begotten Son, uniting herself with a maternal heart with His sacrifice, and lovingly consenting to the immolation of this Victim which she Herself had brought forth” (Lumen Gentium, 58)
Mary’s faith is a model for the Church: just like Mary, the Church has Her own itinerary and Her own journey to travel. It is Mary’s faith that will teach the Church to be faithful, undivided, perseverant and trustful in times of glory and in times of suffering.