At the Annunciation, Mary represents the whole human race

Each taking different paths, theologians come to the same conclusion: Mary represents the whole human race at the time of the Annunciation.

Some follow the path of the Covenant

Just as in the Covenant of Sinai Moses represented all the people, so in the event of Gabriel's annunciation to Mary—presented according to the scheme of an Alliance pact—the Virgin Mary undertakes, on behalf of humanity, to adopt God’s salvific project.

Some follow the path of the spousal (nuptial) Incarnation

At the Incarnation, according to the theology of the Fathers of the Church, "the mystery of the nuptials between God and the human race" took place. The nuptial pact is realized with the spousal "yes" of the Word and the spousal "yes" of Mary, pronounced in the name of all mankind. This is the thought of Saint Thomas. To illustrate the appropriate fashion of Christ's conception being announced to the Virgin, he writes:

"It was appropriate to announce to the Blessed Virgin that she would conceive Christ ... to show that a certain marriage between the Son of God and human nature would take place. And this is why the Annunciation asked for the consent of the Virgin who represented the whole human race."[1]

Others took the path of the messianic expectation

In Mary is concentrated and expressed the messianic expectation of her people and of humanity. Beyond a few rhetorical exasperations, it is the thought that Saint Bernard expresses with great emphasis in his famous sermon In laudibus Virginis Matris IV, 8.

[1] Saint Thomas Aquinas, Summa Theologica III q30 a1

Excerpts from: Ignazio Calabuig, La place du culte marial dans l'Eglise, in Aa Vv, Marie, l'Eglise et la théologie, directed by D. de Boissieu, P. Bordeyne, S. Maggioni, Desclée, Paris 2007, note 104, p. 210

Ignazio Calabuig