There is a better understanding of what the Catholic Church actually teaches about Mary as well as a better appreciation by Catholics of the theological questions that are raised by other Christians regarding Mary. In this environment, scholars from different traditions have reflected upon Marys role as a collaborator of God in salvation history as well as her role in the Communion of Saints.
One very significant effort has been that of four Lutheran, four non-Lutheran Protestants and four Catholic Biblical Scholars, which produced the book, Mary in the New Testament, (New York: Paulist, 1978). Other noteworthy ecumenical works on Mary have been: Mary for All Christians by the Anglican theologian, John Macquarrie (1990); Mary through the Centuries, lectures of the noted scholar Jaroslav Pelikan, at Yale University (1996); Mary is for Everyone, papers given at four International Congresses of the Ecumenical Society of the Blessed Virgin Mary (1997); and Blessed One, Protestant Perspectives on Mary, edited by Beverly Roberts Gaventa and Cynthia L. Rigby.
In reexamining the writings of the original Reformers, scholars have uncovered more sympathy among the Reformers regarding Mary than succeeding generations may have had, as the divisions hardened between what was Catholic and what was Protestant. Catholics and Protestants might be surprised to learn of Martin Luthers reverence for Mary, as can be seen in his Commentary on the Magnificat, written in 1521.
Between 1983 and 1990, Catholics and Lutheran theologians met to discuss the issues related to intercession, the saints and Mary. The summary of these discussions was published inThe One Mediator, the Saints, and Mary: Lutherans and Catholics in Dialogue VII (1992);
Since 1937, Protestant pastors and Catholic priests from France and Switzerland have conducted an ongoing dialogue on ecumenical issues. Initially, they first met at the Cistercian abbey of Notre Dame des Dombes, twenty miles north of Lyons, from which came the name of the group. Presently the group consists of twenty Lutheran or Reformed pastors and twenty Catholic priests. They are a private association, which meets yearly. Over the years, they have issued a number of documents on various theological issues. Between 1991 and 1997, they reflected on Marys role in salvation. The English edition of their reflections, Mary in the Plan of God and in the Communion of Saints, was printed in 2002.
On February 2, 2004, a document was signed by the members of the Anglican-Roman Catholic International Commission (ARCIC), entitled Mary: Grace and Hope in Christ as a statement of the commission which was then submitted to the Pontifical Commission for Promoting Christian Unity and to the Archbishop of Canterbury and the Anglican Consultative Council for further study and evaluation. The document was issued on May 12, 2005, to be used for further study by the churches. It is available on the Vatican website (www.vatican.va) through the Pontifical Council for promoting Christian Unity.
While much progress has been made, the efforts at dialogue need to continue. Pope John Paul II, in his Encyclical, Ut Unum Sint, has included the Churchs beliefs about Mary among the five areas where fuller study is needed before there can be consensus in faith. Two of the other areas, which the Pope identifies as principle issues, also relate to Marian dogma: the relationship between Scripture and tradition as well as the role of the Magisterium in teaching and safeguarding the faith.
We may ask what we intend to achieve by ecumenism. Is it negotiation by which each group agrees to give up something for the good of accommodating each other? Although some people may assume that this might be the process of ecumenism, the better approach is to strive to seek Gods truth together, wanting to have the mind of Christ. Christian unity will come through humbly seeking the unity that already is in God. Christians who accept the truths of the Trinity and Incarnation must recognize that the Eternal Word was united with human nature in Mary. Mary was the location of the union of the divine and human in the one Person, Jesus.
Underlying theological issues related to Marian beliefs:
The concerns of non-Catholic Christians about Mary are not related simply to the person of Mary in herself but are related to other fundamental theological truths that served as the basis for the break at the time of the Reformation. Just as there were differences among the reformers there also are differences in the theologies of the various Protestant denominations. There are several key theological concerns which enter into the discussion of Mary.
Luthers approach to the Justification of Mary:
Luther views Mary from the perspective of his theological principles by which the human person can never be said to possess any virtuous quality other than faith in the saving power of Jesus. Luthers teachings on Mary are part of his understanding of the role of the saints in general for him, in which the saints and Mary are examples of what God can do with weak humanity.
Luther explains his understanding of Mary within his theology of justification, emphasizing grace: Mary also freely ascribes all to Gods grace, not to her merit. For though she was without sin, yet that grace was far too great for her to deserve it in any way. How could a creature deserve to become the Mother of God? It is noteworthy that Luther speaks of her as being without sin.
Luther rejects the notion of merit since he emphasizes that our justification is completely the work of grace. He criticizes Catholic veneration of her as exalting her and so lowering the power of grace. He stresses that Mary does not want us to make an idol of her, stressing her merit, or looking for good things from her but to honor God and have confidence in His grace. 
The Lutherans in the Lutheran-Catholic Dialogue questioned the practice of attributing virtues other than faith to holy persons based on their conviction that faith alone justifies and that Christ alone makes a person holy: In Luthers exposition of the Magnificat, he exalts Mary because she faces her situation by faith alone. An attempt to use Mary or another Christian to extol any other virtue than faith raises the question of undermining living only by faith in Christ.
Luther wrote: I say Mary does not desire to be an idol; she does nothing, God does all. Luthers caution that our attention on Mary should not end with her but be directed to having more confidence in Gods grace may also be understood in a Catholic position. However, Catholics also ascribe all good to God, yet there is a difference in that we believe that Gods grace really changes us and enables to be cooperators with Him in doing good, always relying on His grace.
The Catholic position on the way that grace works in our lives was brought out by the Council of Trent: Justification ¦ consists not only in the forgiveness of sins but also in the sanctification and renewal of the inward being by a willing acceptance of the grace and gifts.  The Council states that while Gods grace initiates and supports any good action, the person can either accept or refuse grace.  In 1998, Lutheran and Catholic leaders signed a Joint Declaration on the Doctrine of Justification seeking a greater convergence on the issues of justification.
In the Lutheran tradition, Gods initiative is emphasized in justifying us while our response is that of our human freedom moved by grace. If the acceptance of justification is the first phase, a second phase follows, which is the carrying out of salvation. Luthers reflection on Marys purification in the temple is used by the Dombes Group to locate Marys good actions within the experience of being already justified. Luther wrote:
She was purified¦although she was not bound by that law and did not need to be purified¦. She was not justified by this work, but being righteous she did it freely and willingly. So also our works should be done, not that we may be justified by them, since, being justified beforehand by faith, we ought to so all things freely and joyfully for the sake of others.
The Dombes Group seems willing to recognize Marys cooperation, if it is seen within the perspective of justification by faith.
It was because Mary had been justified by grace alone and in faith, that she could be associated with Gods work in Christ. Her cooperation was unique in regard to the nature of what she did, for she was the mother of Jesus and raised him. She cooperated in the unique and universal event of salvation. But from the point of view of structure of her status, her cooperation was not different from that of every person justified by grace. It was entirely the fruit of the grace of God.
As Catholics, we would emphasize both the grace of God in a good action as well as human freedom acting as it is aided by grace. Our cooperation is never separate from Gods help.
Issue of human cooperation with God:
Karl Barth, from the Reformed or Calvinist perspective, identifies the Catholic teachings on Mary as the prime example of Catholic principle on which all their important positions are to be regarded and by which they stand and fall.
Reformed theology emphasizes the principle, sola gratia. According to Barth, the Catholic teaching on Mary exalts human cooperation:
In the doctrine and worship of Mary there is disclosed the one heresy of the Roman Catholic Church which explains all the rest. The mother of God of Roman Catholic Marian dogma is quite simply the principle, type, and essence of the human creature co-operating servantlike (ministerialiter) in its own redemption on the basis of prevenient grace, and to that extent the principle, type and essence of the Church. 
Barth has accurately noted the relationship Catholics affirm in comparing Mary and the Church, since both the Church and Mary demonstrate creaturely co-operation with grace. He criticizes these Catholic positions on creaturely co-operation which is also related to the role of the church in cooperating with God:
Not only does it need Christ, but in all seriousness Christ also needs it. As Mary inevitably co-operates in mans redemption as an intercessory power so does the Church in consummating the sacraments¦. the Church of the man who co-operates with grace on the basis of grace.
In fact, Barth has very accurately identified a fundamental Catholic principle that we cooperate with God. Barth objects to the notion not only of cooperation in good works but also of merit. Actually, the Catholic position is nuanced, taking human cooperation seriously enough to consider that our works are meritorious. Nevertheless, human cooperation has to be seen within the context of the Churchs teachings on the importance of grace in every good work, as Thomas Aquinas explains: Man obtains from God as a reward of his operation, what God gave him the power of operation for¦
John Macquarrie, an Anglican theologian, questions Barths objections by noting that even though ultimately salvation is the work of God, the human person is not a puppet or clay to be molded. As Macquarrie points out, the Marian teaching on the Immaculate Conception, is a clear illustration of salvation as a work of Gods grace since the one being conceived can only receive.
Macquarrie points out that during her life Mary had the freedom to respond or not respond to Gods grace:
Now it is the human consent and co-operation with God in the work of salvation that come to expression in the career of Mary. Not for a moment can one deny (or would one want to deny) that salvation is from God and is a work of grace, but God does not force His gifts upon us and we can become His covenant partners only if we give our glad and willing assent. 
As Catholics, we believe, that a woman was preserved from sin by grace, and responded by faith and obedience aided by grace in co-operating in the birth and upbringing of the Son of God. She was made holy by grace but she also freely responded to that grace. As the analogy of Eve/Mary illustrates, Marys cooperation was not passive but active.
The Dombes Group identified human co-operation as an important theological issue. They saw Marys cooperation within her relation with the Three Persons of the Trinity:
Marys cooperation is the fruit of an initiative of the Father who looks upon the lowliness of his servant (Luke 1:48). It also the fruit of the kenosis of the Son who emptied himself¦and humbled himself (Phil 2:7-8). Finally, it is the fruit of the action of the Spirit, who disposes Marys heart to be obedient. That is what happened at the moment of her fiat. Marys humility is the fruit of the Sons humility.
Luther recognizes intercession made to Mary: We ought to call upon her, that for her sake God may grant and do what we request. Thus also all other saints are to be invoked, so that the work may be every way Gods alone. In fact, Luther begins the same homily, asking God to grant him a right understanding: ¦through the intercession and for the sake of His dear Mother Mary!
Nevertheless, Luther asserts that we cannot rely on the intercession of another person, base your salvation on no other works than those God works in you alone, as you see the Virgin Mary do here. To let the intercessions of others assist you in this is right and proper; we ought all to pray and work for one another. But no one should depend on the works of others, without the works of God in himself.
The Lutheran theologians who took part in the Lutheran-Catholic Dialogue expressed their concern regarding the invocations of the saints and of Mary, which they see as a challenge to the sole mediatorship of Christ, through whom God pours out grace in the Holy Spirit and the justifying faith of the believer. The Lutheran members could accept the saints as examples of Christian life and faith. The Lutherans believe that angels and saints pray for us within the context of Jesus as the one mediator. 
The Catholic participants in the Lutheran-Catholic Dialogue asserted that the mediation of Mary does not mean that Mary is a source of grace in herself but rather her merciful love is an expression and reflection of the mercy of Christ himself. 
The Catholic members addressed the question of intercession by saying that Jesus is never alone but is always in the company of His friends, living and dead. Saints illustrate how Gods grace can work in us, they are patterns of holiness and they pray for us. In the Catholic view, we are bonded with millions of other believers throughout the world and throughout time. Those who have preceded us in faith are still connected with us.
Catholics see the practice of invoking the saints as an extension of the New Testament practice of intercession (Rom 15:30-32; 2 Cor 1:11; Eph 4:19; Col 4:3) and of the prayer of the righteous (Jas 5:16). Those in heaven have a heightened charity towards those on earth. Marys intercession has exception power because of her divine motherhood.
It was recognized that prayer was being used in a broad sense when directed to Mary and the saints. Protestants had no difficulty with praise directed to God for the works God has done in Mary. This could even be seen as being done with Mary.
For Catholics, intercession was seen as a form of communion. Catholics recognized there have been excesses in Marian piety, which have not been curbed by the Churchs leaders. Nevertheless, the most frequent invocation is to ask Mary to pray for us, in a similar way as the saints are asked to pray for us.
Catholics and Protestants agreed that Mary should be honored and God should be praised for the graces given to her. She should be imitated and we should unite ourselves in praising the Father through her. The Protestants were reluctant to invoke her whereas Catholics entrust themselves to her prayers.
The Anglican-Catholic Dialogue acknowledged that the English Reformers rejected the notion of the invocation of saints yet the Council of Trent reaffirmed it, emphasizing as it did so that such requests were made to God, through his Son our Lord Jesus Christ, who is our sole redeemer and savior (DS 1821).
The Anglican-Catholic document recognized that all ministries in the church, especially those of word and sacrament, mediate the grace of God through human beings. These ministries serve the mediation of Christ and have their power in it. Asking prayers of our brothers and sisters does not diminish the mediatorship of Christ but shows its power through the Spirit.
In the experience of communion of prayer, we are aware of the support of those living and dead. With this understanding, it seems that asking saints for prayers is not to be seen as unscriptural, although not directly taught by the scriptures as a required element. Our prayers are not addressed to the saints, but they are asked to pray for us, though this should not be done in a manner that blurs the Trinitarian economy of grace. The authors of the Anglican-Catholic document state: Affirming together unambiguously Christs unique mediation, which bears fruit in the life of the Church, we do not consider the practice of asking Mary and the saints to pray for us as communion dividing.