Objection 2: Calling the Blessed Virgin Mary, "Co-redemptrix" is against proper Christian ecumenism, as it leads to division between Catholics and other Christians.
Arguably the most commonly posed objection to the use of Co-redemptrix (let alone any potential definition of the doctrine) is its perceived opposition to Christian ecumenism. Therefore we must begin with an accurate definition of authentic Christian ecumenism and its appropriate corresponding activity as understood by the Catholic Church.
In his papal document on ecumenism, Ut Unum Sint, ("that they all may be one" Jn. 17:21), Pope John Paul II defines authentic Christian ecumenism in terms of prayer "as the soul" and dialogue "as the body" working towards the ultimate goal of true and lasting Christian unity. At the same time, the Catholic imperative to work and strive for Christian unity does not permit in any degree the reduction or dilution of Catholic doctrinal teaching, as such would both lack Catholic integrity and concurrently be misleading in dialogue with other non-Catholic Christians as to what the Catholic Church truly believes.
As the Second Vatican Council clearly teaches in terms of ecumenical dialogue: "It is, of course, essential that doctrine be clearly presented in its entirety. Nothing is so foreign to the spirit of ecumenism as a false conciliatory approach which harms the purity of Catholic doctrine and obscures its assured genuine meaning."
John Paul II further explains:
With regard to the study of areas of disagreement, the Council requires that the whole body of doctrine be clearly presented. At the same time, it asks that the manner and method of expounding the Catholic faith should not be a hindrance to dialogue with our brothers and sisters...Full communion of course will have to come about through the acceptance of the whole truth into which the Holy Spirit guides Christ's disciples. Hence all forms of reductionism or facile "agreement" must be absolutely avoided.
An accurate understanding then of ecumenism from the Catholic perspective is the critical Church mandate to pray, to dialogue, and to work together in charity and in truth in the seeking of true Christian unity among all brothers and sisters in Christ, but without any compromise in presenting the full doctrinal teachings of the Church. The present pope, so personally dedicated to authentic Christian unity, again affirms: "The unity willed by God can be attained only by the adherence of all to the content of revealed faith in its entirety. In matters of faith, compromise is in contradiction with God who is Truth. In the Body of Christ, 'the way, the truth, and the life' (Jn.14:6), who could consider legitimate a reconciliation brought about at the expense of the truth?"
Let us now apply this understanding of ecumenism to the question of Mary Co-redemptrix. The Co-redemptrix title for Mary has been used in repeated papal teaching, and the doctrine of Marian co-redemption as Mary's unique participation with and under Jesus Christ in the redemption of humanity constitutes the repeated doctrinal teaching of the Second Vatican Council:
...She devoted herself totally, as handmaid of the Lord, to the person and work of her Son, under and with him, serving the mystery of redemption, by the grace of Almighty God. Rightly, therefore, the Fathers see Mary not merely as passively engaged by God, but as freely cooperating in the work of man's salvation through faith and obedience.
Thus the Blessed Virgin advanced in her pilgrimage of faith, and faithfully persevered in union with her Son unto the cross, where she stood, in keeping with the divine plan, enduring with her only begotten Son the intensity of his suffering, associated herself with his sacrifice in her mother's heart, and lovingly consenting to the immolation of this victim which was born of her.
She conceived, brought forth, and nourished Christ, she presented Him to the Father in the temple, shared her Son's suffering 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.
Thereby, there is no question that Marian Co-redemption constitutes the doctrinal teaching of the Catholic Church and as such must be presented in any true articulation of Catholic teaching, which critically includes the domain of true ecumenical dialogue.
To therefore claim that Mary Co-redemptrix in title and doctrine is in any way contrary to the ecumenical mission of the Church is fundamentally to misunderstand the ecumenical mission of the Church itself. Full Catholic doctrine, including the doctrine of Marian co-redemption, must be included for any true dialogue seeking Christian unity. Moreover, the purposeful absence of Mary Co-redemptrix in full ecumenical dialogue and in the overall ecumenical mission of the Church would lack integrity and justice for the Catholic ecumenist towards non-Catholic Christians who have presumably, on their part, brought the full teachings of their particular ecclesial body to the tables of dialogue. To return to the Christian admonition of John Paul II: "In the Body of Christ, 'the way, the truth, and the life' (Jn.14:6), who could consider legitimate a reconciliation brought about at the expense of the truth?"
Therefore calling the Blessed Virgin Mary a "Co-redemptrix" in light of Christian Scripture and Christian Tradition is in no sense contrary to ecumenism, but rather constitutes an essential element of the Christian integrity demanded by true ecumenism, since Marian Co-redemption constitutes a doctrinal teaching of the Catholic Church.
In fact, if the doctrine of Co-redemptrix presently constitutes a source of confusion for some Christians, connoting for some an image of goddess or other concepts of Marian excesses, then it appears all the more appropriate that a clear articulation of this Marian doctrine be given to brother and sister Christians in ecumenical dialogue. There is also the potential benefit of a formal papal definition providing the greatest possible clarity from the highest possible Catholic authority. In the words of the late John Cardinal O'Connor of New York: "Clearly, a formal papal definition would be articulated in such precise terminology that other Christians would lose their anxiety that we do not distinguish adequately between Mary's unique association with Christ and the redemptive power exercised by Christ alone."
Another legitimate ecumenical perspective on Marian co-redemption and her subsequent spiritual motherhood is that as spiritual mother of all peoples, Mary can be a principal means of Christian unity among divided Christian brothers and sisters, rather than being its prime obstacle. Lutheran pastor, Rev. Dr. Charles Dickson, calls on Protestant Christianity to re-examine the documented positive Marian defense and devotion of many of its own founders, as manifested, for example, in the words of Martin Luther in his Commentary on the Magnificat: "May the tender Mother of God herself procure for me the spirit of wisdom profitably and thoroughly to expound this song of hers...May Christ grant us a right understanding...through the intercession and for the sake of His dear Mother Mary...."
Luther goes on to call Mary the "workshop of God," the "Queen of heaven," and states: "The Virgin Mary means to say simply that her praise will be sung from one generation to another so that there will never be a time when she will not be praised."
On the role of Mary's universal spiritual motherhood as an instrument of Christian unity, Dr. Dickson comments further:
"In our time, we are still faced with the tragic divisions among the world's Christians. Yet, standing on the brink of a bright new ecumenical age, Mary as model of catholicity, or universality, becomes even more important. In the course of many centuries from the beginning of the Church, from the time of Mary and the Apostles, the motherhood of the Church was one. This fundamental motherhood cannot vanish, even though divisions occur. Mary, through her motherhood, maintains the universality of Christ's flock. As the entire Christian community turns to her, the possibility of a new birth, a reconciliation, increases. So Mary, the mother of the Church, is also a source of reconciliation among her scattered and divided children."