Yet these will seem insufficient for most Protestants to explain Mary's centrality in actual Catholic practice. It is easy to see the unprecedented distinction of the Annunciation and the magnificent faith in her Fiat. I can also readily concede her essential function in salvation history, for Mary was in a sense the gatekeeper of the Incarnation. But that only scratches the surface, only gets us as far as doctrine. Whence the rosaries, prayers, devotions, and apparitions?
The answer, naturally enough, lies in another set of typologies.
In my post on the Immaculate Conception, I wrote that Mary's "justly-celebrated fiat is one of the defining moments of Creation: the pinnacle of all the patriarchs, of all the prophets, and all the people of God." This is true on its own, but hints at a deeper truth.
On the one hand, the nation of Israel may be seen as a typology of Mary.
My Bible's study notes on Revelations 12:1 states that the image of the woman in labor, giving birth to the child Christ, is "probably a symbolic reference to the believing Messianic community." This is, on its face, a pretty clear attempt to avoid a Marian interpretation of the passage. However, that doesn't mean they aren't both true. Mary is the fulfillment of Israel -- she is prefigured not only by the Ark of the Covenant and by the Temple, but also to a certain extent by all the key women of Israel's history: Miriam, Rahab, Deborah, Hannah, and Bathsheba, among others. They are the threads in the tapestry of Mary's life.
The people of Israel were prepared from the days of Abraham precisely for the arrival of the Messiah. They were to be the nation through which all nations would be blessed. In the same way, Mary was prepared from before her birth to be the vessel of Christ's Incarnation, to be the woman through which all of humanity would be blessed.
There is another sense in which Israel prefigured Mary, for the history of the Jews is one of slavery and suffering, of a painful purification and ultimately redemptive suffering. Israel typifies Jesus, for He is the ultimate example of suffering unto goodness. But we cannot forget the words of Simeon when Mary brought the child Christ to the Temple:
Behold this child is appointed for the fall and rise of many in Israel, and for a sign to be opposed -- and a sword will pierce even your own soul -- to the end that thoughts from many hearts will be revealed (Luke 2:34-35).
This, incidentally, is what Catholics mean when they address Mary as "co-redemptrix." It is not a title to diminish Christ's sacrifice, nor to imply that Mary was in any way responsible for our atonement or salvation. It merely indicates that Mary shared in the suffering of her Son's agony. Can we begin to fathom the mother's anguish, as she watched them torture her Son, as she stood before Christ hanging on a cross (John 19:25) and watched Him take His final breaths? Her soul was pierced by sword just as surely as his side was pierced by spear.
Yet Mary does not suffer alone. She suffered just as all Christians are called to "take up their cross daily" (Luke 9:23), and for the same reason that Paul wrote, "in my flesh I do my share on behalf of His Body, which is the Church, in filling up what is lacking in Christ's afflictions" (Colossians 1:24). Christ redeemed suffering, and conquered death. The stain of sin, the evil of fallen nature, has become in His hands a vehicle of perfect love. This is why the Church glorifies the martyrs, and why the lives of the saints are marked with suffering.
In this way, Mary is herself a typology of the Church.
This extends far beyond an understanding of redemptive suffering. Mary is truly the archetypal Christian. From her first appearance she expressed the Fiat, those undying words of faith: "Behold, the handmaid of the Lord; may it be done to me according to your word" (Luke 1:38). "My soul magnifies the Lord, and my spirit has rejoiced in God my Savior," she cries in the remarkable Magnificat (Luke 1:46-47). Luke repeats several times during his early chapters that Mary "treasured all these things, pondering them in their heart" (Luke 2:19, 2:51, et al.), holding firmly on to the deposit of the faith.
Perhaps most notable is Mary's role at the beginning of the Gospel of John:
On the third day there was a wedding in Cana of Galilee, and the mother of Jesus was there; and both Jesus and his disciples were invited to the wedding. When the wine ran out, the mother of Jesus said to Him, "They have no wine." And Jesus said to her, "Woman, what to me and to you? My hour has not yet come." His mother said to the servants, "Whatever he says to you, do it (John 2:1-5).
Some Protestants have claimed that Jesus' words in this passage actually marginalize and diminish Mary. This strikes me as an error, if only because Christ could not have violated the commandment to "Honor thy father and mother." His address to Mary as "Woman" is actually considered evidence for the typological reading of Mary as a second Eve, and this passage is sometimes considered in that light. The question itself is sometimes translated as an almost bemused "What does that have to do with us?" (NASB) or the more notoriously dismissive "What have I to do with thee?" (as in the King James translation). In fact, the literal translation -- "What to me and to you?" -- is a well-worn Hebrew idiom that is basically an open-ended interrogative, meaning "Why are you here?" or "What is your question?" In this case, especially in light of Mary's response, the likeliest interpretation would seem to be a simple "What are you asking of me?"
Just before the Transfiguration, Jesus asks His disciples, "Who do the people say that I am?" (Luke 9:18) They respond with a litany of long-dead prophets. "But who do you say that I am?" The question is open-ended, and (importantly) precedes any statement by Jesus Himself that would provide an answer. This is the moment of the Petrine confession, the first point in the Gospels in which Jesus is revealed to be divine. "You are the Christ, the Son of the Living God" (Matthew 16:16). Peter's confession was a leap of faith.
In the same way, Jesus' question to Mary at Cana is not leading but open-ended, allowing room for Mary's response of faith. In this moment Mary does not presume to direct her Son, but merely expresses her reliance on His will and her readiness to obey, by placing her servants at His disposal. As a result of this, Christ directs the servants to fill the massive jugs with water and pour them for the guests, turning the water into wine. It is once again Mary's expression of faith that propels the next movement of the Incarnation: His first miracle, that launches His public ministry.
Mary is a typology for the church. But she is also the mother to another Type: Christ Himself.
Is it really necessary to cite the many passages in which Christians are called to model ourselves after Christ, to live in Christ, to clothe ourselves with Christ? Let it suffice to say, that as His disciples we walk in His steps.
If indeed Christ lived without sin, and if indeed we take Him at His word that He came "not to abolish but to fulfill" the Law and the Prophet, then we see that Christ obeyed the precepts of the Law. Specifically, He obeyed the commandment to honor His father and mother. This, then, is why Catholics honor Mary, for they seek to imitate His life in that manner too.
John never names himself in his Gospel, but only identifies himself as "the disciple Jesus loved." I suspect this is partly out of an almost coy modesty, but it is at least partly done to invite other Christians to walk beside Christ for themselves, to see through his eyes and bear witness to the Gospel. This invitation should help us understand a passage from John's account of the Passion. Hanging on the cross before His death, "when Jesus then saw His mother and the disciple whom He loved standing nearby, He said to His mother, 'Woman behold, your son!" Then He said to the disciple, "Behold your mother!" From that hour the disciple took her into his own household" (John 19:26-27).
Christ is a type for the Church, for the life of a disciple, and He gave to the great disciple the command to take the Mother of God into his household and honor her accordingly. This is Catholics mean when they speak of Mary's "spiritual motherhood of the Church." If we live in Christ, we will live out His respect for her, and treat her with the love and devotion proper for a child to give his mother. Mary is the mother of the Church.