Vatican Council II, Dogmatic Constitution on the Church, 21 November 1964.
Excerpts from CHAPTER VIII: OUR LADY, from sections 60-65.
Mary's Role in the Church
Mary's function as mother of men in no way obscures or diminishes this unique mediation of Christ, but rather shows its power. But the Blessed Virgin's salutary influence on men originates not in any inner necessity but in the disposition of God. It flows forth from the superabundance of the merits of Christ, rests on his mediation, depends entirely on it and draws all its power from it. It does not hinder in any way the immediate union of the faithful with Christ but on the contrary fosters it.
The predestination of the Blessed Virgin as Mother of God was associated with the incarnation of the divine word: in the designs of divine Providence she was the gracious mother of the divine Redeemer here on earth, and above all others and in a singular way the generous associate and humble handmaid of the Lord. She conceived, brought forth, and nourished Christ, she presented him to the Father in the temple, shared her Son's sufferings as he died on the cross. Thus, in a wholly singular way she cooperated by her obedience, faith, hope and burning charity in the work of the Savior in restoring supernatural life to souls. For this reason she is a mother to us in the order of grace.
This motherhood of Mary in the order of grace continues uninterruptedly from the consent which she loyally gave at the Annunciation and which she sustained without wavering beneath the cross, until the eternal fulfillment of all the elect. Taken up to heaven she did not lay aside this saving office but by her manifold intercession continues to bring us the gifts of eternal salvation. By her maternal charity, she cares for the brethren of her Son, who still journey on earth surrounded by dangers and difficulties, until they are led into their blessed home. Therefore the Blessed Virgin is invoked in the Church under the titles of Advocate, Helper, Benefactress, and Mediatrix. This, however, is so understood that it neither takes away anything from nor adds anything to the dignity and efficacy of Christ the one Mediator.
No creature could ever be counted along with the Incarnate Word and Redeemer; but just as the priesthood of Christ is shared in various ways both by his ministers and the faithful, and as the one goodness of God is radiated in different ways among his creatures, so also the unique mediation of the Redeemer does not exclude but rather gives rise to a manifold cooperation which is but a sharing in this one source.
The Church does not hesitate to profess this subordinate role of Mary, which it constantly experiences and recommends to the heartfelt attention of the faithful, so that encouraged by this maternal help they may the more closely adhere to the Mediator and Redeemer.
Mary, type or figure of the Church
By reason of the gift and role of her divine motherhood, by which she is united with her Son, the Redeemer, and with her unique graces and functions, the Blessed Virgin is also intimately united to the Church. As St. Ambrose taught, the Mother of God is a type of the Church in the order of faith, charity, and perfect union with Christ. For in the mystery of the Church, which is itself rightly called mother and virgin, the Blessed Virgin stands out in eminent and singular fashion as exemplar both of virgin and mother. Through her faith and obedience she gave birth on earth to the very Son of the Father, not through the knowledge of man but by the overshadowing of the Holy Spirit, in the manner of a new Eve who placed her faith, not in the serpent of old but in God's messenger without waivering in doubt. The Son whom she brought forth is he whom God placed as the first born among many brethren (Rom. 8:29), that is, the faithful, in whose generation and formation she cooperates with a mother's love.
The Church indeed contemplating her hidden sanctity, imitating her charity and faithfully fulfilling the Father's will, by receiving the word of God in faith becomes herself a mother. By preaching and baptism she brings forth sons, who are conceived of the Holy Spirit and born of God, to a new and immortal life. She herself is a virgin, who keeps in its entirety and purity the faith she pledged to her spouse. Imitating the mother of her Lord, and by the power of the Holy Spirit, she keeps intact faith, firm hope and sincere charity.
But while in the most Blessed Virgin the Church has already reached that perfection whereby she exists without spot or wrinkle (cf. Eph. 5:27), the faithful still strive to conquer sin and increase in holiness. And so they turn their eyes to Mary who shines forth to the whole community of the elect as the model of virtues. Devoutly meditating on her and contemplating her in the light of the Word made man, the Church reverently penetrates more deeply into the great mystery of the Incarnation and becomes more and more like her spouse. Having entered deeply into the history of salvation, Mary, in a way, unites in her person and re-echoes the most important doctrines of the faith: and when she is the subject of preaching and veneration she prompts the faithful to come to her Son, to his sacrifice and to the love of the Father. Seeking after the glory of Christ, the Church becomes more like her lofty type, and continually progresses in faith, hope and charity, seeking and doing the will of God in all things. The Church, therefore, in her apostolic work too, rightly looks to her who gave birth to Christ, who was thus conceived of the Holy Spirit and born of a virgin, in order that through the Church he could be born and increase in the hearts of the faithful. In her life the Virgin has been a model of that motherly love with which all who join in the Church's apostolic mission for the regeneration of mankind should be animated.
15. Cfr. Kleutgen, textus reformatus De mysterio Verbi incarnati, cap. IV: Mansi 53, 290. Cfr. S. Andreas Cret., In nat. Mariae, sermo 4: PG 97, 865 A. - S. Germanus Constantinop., In annunt. Deiparae: PG 98, 321 BC. In dorm. Deiparae, III: col. 361 D.S. Io. Damascenus, In dorm. B. V. Mariae, Hom. 1, 8: PG 96, 712 BC - 713 A.
16. Cfr. Leo XIII, Litt. Encycl. Adiutricem populi, 5 sept. 1895: ASS 15 (1895-96), P. 303. - S. Pius X, Litt. Encycl. Ad diem illum, 2 febr. 1904: Acta, I, p. 154; Denz. 1978 a (3370). - Pius XI, Litt. Encycl. Miserentissimus, 8 maii 1928: AAS 20 (1928) P. 178. Pius XII, Nuntius Radioph., 13 maii 1946: AAS 38 (1946) P. 266.
17. S. Ambrosius, Epist. 63: PL 16, 1218.
18. S. Ambrosius, Expos. Lc. II, 7: PL 15, 1555.
19. Cfr. Ps.-Petrus Dam., Serm. 63: PL 144, 861 AB. - Godefridus a S. Victore. In nat. B. M., Ms. Paris, Mazarine, 1002, fol. 109 r. - Gerhohus Reich., De gloria et honore Filii hominis, 10: PL 194,1105AB.
20. S. Ambrosius, l. c. et Expos. Lc. X, 24-25: PL 15, 1810. - S. Augustinus, In lo. Tr. 13, 12: PL 35, 1499. Cfr. Serm. 191, 2, 3: PL 38, 1010; etc. Cfr. etiam Ven. Beda, In Lc. Expos. I, cap. 2: PL 92, 330. - Isaac de Stella, Serm. 51: PL 194, 1863 A.
21. Sub tuum praesidium.
22. Conc. Nicaenum II, anno 787: Mansi 13, 378-379; Denz. 302 (600-601) .conc. Trident., sess. 25: Mansi 33, 171-172.
23. Cfr. Pius XII, Nuntius radioph., 24 oct. 1954: AAS 46 (1954) P. 679. Litt. Encycl. Ad coeli Reginam, 11 oct. 1954: AAS 46 (1954) P. 637.
Excerpted from Vatican II, Dogmatic Constitution on the Church Lumen gentium, 21 November 1964