In his plenary address to the Congregation for the Doctrine of the Faith (January 15, 2010), Pope Benedict XVI affirmed that the successor of Peter is the primary guardian and defender of the sacred deposit. His ministry towards unity involves unity of faith above all else so that there be one flock and one shepherd. Ecumenism, in the proper sense of the term, is nothing more than an outward manifestation of this constant ministry towards unity. In other words, the ultimate goal of ecumenism is the “full and visible communion of the disciples of the Lord”. For Pope Benedict XVI, the Apostolic Constitution Anglicanorum Ceotibus -- far from being contrary to true ecumenism --
represents an example of its ultimate aim towards the perfection of visible Catholic unity. In this manner, Pope Benedict XVI once again defends "continuity" with respect to Tradition and Vatican II while dispelling false notions (rupture) with respect to ecumenism.
Ecumenism: Progression of Stages
This “ministry towards unity” is always present, however, it need not be carried out in exactly the same (practical) manner in every particular circumstance. Nor must it necessarily take place suddenly or all at once. What this means is that the practical guidelines or norms for ecumenical activity can be revised as deemed prudent by the Holy See. In this sense, the Vatican II Decree on Ecumenism -- while preserving the continuity of immutable principles -- can be seen as an update to the practical guidelines for ecumenical activity that were in place prior to Vatican II. The Vatican II decree gives a broad outline for the various practical steps or stages of ecumenical activity oriented towards full visible unity in the Catholic Church (UR, 4).
Stage 1: Charity in Truth
“…first, every effort to avoid expressions, judgments and actions which do not represent the condition of our separated brethren with truth and fairness and so make mutual relations with them more difficult…”
Stage 2: Dialogue
One does not engage in "dialogue" merely for its own sake. The purpose of such theological exchanges is mutual understanding in order to overcome those differences that represent obstacles to full Catholic unity -- one faith, one baptism, one Lord...
“…then, ‘dialogue’ between competent experts from different Churches and Communities… In such dialogue, everyone gains a truer knowledge and more just appreciation of the teaching and religious life of both Communions…”
Stage 3: Cooperation
Christians should work together to build on the level or degree of unity that exists between them. In this way, the various Christian communities ought to join together in causes that promote Christian and moral values for the good of individuals and society: life, marriage, freedom of religion in the public square, etc.
“In addition, the way is prepared for cooperation between them in the duties for the common good of humanity which are demanded by every Christian conscience; and, wherever this is allowed, there is prayer in common.”
Stage 4: Conversion of Hearts
“Finally, all are led to examine their own faithfulness to Christ's will for the Church and accordingly to undertake with vigor the task of renewal and reform.”
Stage 5: Final Preparation and Reconciliation
The various preliminary stages above are supposed to lead to conversion in the sense of formal enterance into the Catholic Church (i.e., "full and visible communion"). Therefore, this last step is not considered ecumenism, strictly speaking, but rather is considered as the ultimate goal of ecumenism.
“When such actions are undertaken prudently and patiently by the Catholic faithful, with the attentive guidance of their bishops, they promote justice and truth, concord and collaboration, as well as the spirit of brotherly love and unity. This is the way that, when the obstacles to perfect ecclesiastical communion have been gradually overcome, all Christians will at last, in a common celebration of the Eucharist, be gathered into the one and only Church in that unity which Christ bestowed on His Church from the beginning. We believe that this unity subsists in the Catholic Church as something she can never lose, and we hope that it will continue to increase until the end of time… However, it is evident that, when individuals wish for full Catholic communion, their preparation and reconciliation is an undertaking which of its nature is distinct from ecumenical action. But there is no opposition between the two, since both proceed from the marvelous ways of God.”
O GOD, Who settest straight what has gone astray, and gatherest together what is scattered, and keepest what Thou hast gathered together; we beseech Thee in Thy mercy to pour down on Christian people the grace of union with Thee, that, putting disunion aside and joining themselves to the true Shepherd of Thy Church, they may be able to render Thee worthy service. Through our Lord. (Collect, Mass For The Unity of The Church, 1962 Missal)