4 But since the salvation of our race was accomplished by the mystery of the Cross, and since the Church, dispenser of that salvation after the triumph of Christ, was founded upon earth and instituted, Providence established a new order for a new people. The consideration of the Divine counsels is united to the great sentiment of religion. The Eternal Son of God, about to take upon Him our nature for the saving and ennobling of man, and about to consummate thus a mystical union between Himself and all mankind, did not accomplish His design without adding there the free consent of the elect Mother, who represented in some sort all human kind, according to the illustrious and just opinion of St. Thomas, who says that the Annunciation was effected with the consent of the Virgin standing in the place of humanity.(5) With equal truth may it be also affirmed that, by the will of God, Mary is the intermediary through whom is distributed unto us this immense treasure of mercies gathered by God, for mercy and truth were created by Jesus Christ.(6) Thus as no man goeth to the Father but by the Son, so no man goeth to Christ but by His Mother. How great are the goodness and mercy revealed in this design of God! What a correspondence with the frailty of man! We believe in the infinite goodness of the Most High, and we rejoice in it; we believe also in His justice and we fear it. We adore the beloved Saviour, lavish of His blood and of His life; we dread the inexorable Judge. Thus do those whose actions have disturbed their consciences need an intercessor mighty in favour with God, merciful enough not to reject the cause of the desperate, merciful enough to lift up again towards hope in the divine mercy the afflicted and the broken down. Mary is this glorious intermediary; she is the mighty Mother of the Almighty; but-what is still sweeter - she is gentle, extreme in tenderness, of a limitless loving-kindness. As such God gave her to us. Having chosen her for the Mother of His only begotten Son, He taught her all a mother's feeling that breathes nothing but pardon and love. Such Christ desired she should be, for He consented to be subject to Mary and to obey her as a son a mother. Such He proclaimed her from the cross when he entrusted to her care and love the whole of the race of man in the person of His disciple John. Such, finally, she proves herself by her courage in gathering in the heritage of the enormous labours of her Son, and in accepting the charge of her maternal duties towards us all.
Source: Octobri Mense (Vatican.va)