The Blessed Virgin Mary, Mother of God, participated in an altogether unique way in the Mystery of Faith, the Mystery of the Redemptive Incarnation, and is rightly called Co-Redemptrix. So, too, to the degree that we unite our hearts, one with her Immaculate Heart, to the Most Sacred Heart of Jesus, we participate in the saving mission of Christ. We can rightly be called co-redeemers. In the words of Saint John Apostle and Evangelist, we are called to be in Christ “fellow workers in the truth.” Our Lord Himself makes clear the intimacy of our relationship with Him, when He declares: “If any man would come after me, let him deny himself and take up his cross daily and follow me.” In addressing this International Conference on the Blessed Virgin Mary in Dogma and Worship, I want to present the unique share in the mission of Christ the King, the mission of the Redemptive Incarnation, which belongs to the Virgin Mother of God as Co-Redemptrix and our share in the same mission as co-redeemers.

The apparitions of the Virgin Mother of God at Tepeyac Hill in present-day Mexico City help us, in a particular way, to understand her mission and our corresponding mission. In fact, Our Lady’s children of Mexico, guadalupanos and guadalupanas, have always understood their mission in the world as service of Christ the King under the maternal care of His Mother whom He gave to us as our Mother as He was dying on the cross for our eternal salvation. Blessed Miguel Pro wrote two short prayers on the wall of the prison in which he was held before he was martyred on November 23, 1927, by a firing squad during the bloody persecution of the Church in Mexico: “¡Viva Cristo Rey! ¡Viva la Virgen de Guadalupe!” (Long live Christ the King! Long live the Virgen of Guadalupe!). So, too, Saint José Sanchez del Río, as he was cruelly tortured and killed, also by firing squad on February 10, 1928, repeatedly exclaimed: “¡Viva Cristo Rey! ¡Viva Santa Maria di Guadalupe!” (Long live Christ the King! Long live Holy Mary of Guadalupe!). Even as the Virgin Mother of God took the wine stewards at the Wedding Feast of Cana to her Divine Son for the remedy of their great woe, instructing them: “Do whatever he tells you,” so she accompanied these heroes of the faith to give their lives in doing God’s will. So, too, she draws our hearts to her Immaculate Heart leading us to give our hearts totally to the Sacred Heart of Jesus, even to the shedding of our blood with Him for the glory of God and the salvation of souls.

Pius IX:
Ineffabilis Deus, 1854

Pope Leo XIII:
Encyclical Supremi apostolatus officio, 1883
Encyclical Jucunda semper, 1894
Apostolic constitution Ubi primum, 1898
Encyclical Adjutricem populi, 1895

Leo XIII’s encyclicals (including Jucunda semper / Iucunda semper of 1894, Supremi apostolatus officio, Adjutricem populi, and related texts) repeatedly describe Mary as associated with Christ in the work of salvation, offering her Son at the cross, and sharing in the procurement of human redemption. Some English renderings insert “co-Redemptress”; the underlying Latin describes the role without always employing that precise compound. Pius IX’s 1854 Ineffabilis Deus defines the Immaculate Conception in view of the merits of Christ and presents Mary as uniquely prepared for her place in the economy of salvation, but does not use the title “Co-Redemptrix.” Pius XII’s Mystici Corporis (1943) and Ad caeli Reginam (1954) describe her offering of her Son on Calvary and her association with the new Adam in redemption, again without always employing the exact title.

Pius X:
Encyclical Ad diem illum, 1904
During the pontificate of Pius X, a decree from the Holy Office on June 26, 1913, praised “the custom of adding after the name of Jesus that of His Mother, our Co-Redemptrix, the Blessed Virgin Mary.” The same congregation granted an indulgence for the recitation of the prayer in which Mary is called “co-redemptrix of the human race” on January 22, 1914.

Benedict XV:
Apostolic Letter Inter Sodalicia, March 22, 1918 states that Mary, suffering and nearly dying with her Son and offering him to divine justice insofar as it depended on her, can rightly be said to have “redeemed the human race together with Christ” (Ipsam cum Christo humanum genus redemisse).

Pius XI:
He is the first pope to use the term co-redemptrix. In his message to the pilgrims of Lourdes for the Jubilee of the Redemption, he made this prayer: “O Mother of piety and mercy, who as Co-Redemptrix stood by your most sweet Son suffering with Him when He consummated the redemption of the human race on the altar of the cross ... preserve in us, we beg, day by day, the precious fruits of the Redemption and of your compassion” (April 29, 1935).

In a 30 November 1933 address to pilgrims from Vicenza he said the Redeemer associated his Mother in the work and that “we invoke her under the title of Coredemptrix.” His 29 April 1935 radio message to Lourdes contains the prayer quoted in the post almost verbatim: “O Mother of piety and mercy, who as Co-Redemptrix stood by your most sweet Son suffering with Him when He consummated the redemption of the human race on the altar of the cross.” The 1923 letter Explorata res states that the sorrowful Virgin “shared in the work of redemption with Jesus Christ.”

Pius XII:
Encyclical Mystici Corporis (1943)
Encyclical Ad caeli Reginam (1954)

The 4 November 2025 Doctrinal Note Mater Populi Fidelis was issued by the Dicastery for the Doctrine of the Faith (signed by Cardinal Víctor Manuel Fernández and approved by Pope Leo XIV). The note states that the title “Co-redemptrix” “risks obscuring Christ’s unique salvific mediation and can therefore create confusion and an imbalance in the harmony of the truths of the Christian faith,” and that when an expression requires repeated explanations it becomes unhelpful.