Christian ecumenism is the promotion of unity or cooperation between distinct religious groups or denominations of the Christian religion, more or less broadly defined. For the purposes of this article, ecumenism in this sense is distinguished from interfaith pluralism, for reasons discussed immediately below.

Table of contents
1 Distinguished from interfaith pluralism
2 The promotion of the unity of Christianity dogmatically defined
3 The problem of three houses
4 Signs

Distinguished from interfaith pluralism

Because the meaning of "Christianity" is diverse, the description of what is meant by Christian ecumenism is equally diverse.

On the one hand, ecumenism is "interfaith dialogue" between representatives of diverse faiths, not necessarily with the intention of reconciling the professors of other faiths into full, organic unity with one another but simply to promote better relations. With some Christian perspectives on ecumenism, there is no other principle of ecumenism than this. They aim only toward the promotion of toleration, mutual respect and cooperation, whether between Christian churches and denominations, or between Christianity and other faiths. Thus, the World Council of Churches is an instrument in both, the Ecumenical Movement and the Interfaith Movement. However, this is not the case for all Christian ecumenical initiatives; and it would be difficult if not impossible to discuss them together, when much of the Christian world makes a definite difference between the two ideas. Therefore, readers are referred to the thorough discussion of ecumenism in the sense of the promotion of mutual appreciation and improvement between diverse religions, under the entry on religious pluralism.

On the other hand, ecumenism means the aim to reconcile all who profess Christian faith, into a single, visible organization, for example, through union with the Roman Catholic Church, or the Orthodox Church. Ecumenism in this sense focuses on the special problem of the relationship between Christian denominations, where Christianity is dogmatically defined.

The promotion of the unity of Christianity dogmatically defined

For a significantly representative part of the Christian world, the highest aim of the Christian faith is the reconciliation of all divided humanity into a full and conscious union with one Christian Church, visibly united in the sense of governmental accountability between all of its parts and the whole. At a minimum, the desire is expressed in many places by official Christendom, that all who profess faith in Christ in sincerity, would be more fully cooperative and mutually correcting of one another.

The problem of three houses

Surveying the landscape from miles above the problem, the scope of Christian ecumenism is usually described in terms of the three largest divisions of Christendom: Catholic, Orthodox, and Protestant. This disguises the complexity of these divisions, as though each part represents one of three equally definable entities, and as though these divisions represent the most serious differences that would need to be overcome in order to realize the objective of mutual understanding among all Christians, let alone full reconciliation. Nevertheless, it is basically true that, the puzzle of ecumenism is a problem concerning primarily these three houses, each of which presents its own distinctive challenge to finding agreement on the real extent of Christian unity.

Eastern Orthodoxy: the church at home with itself

Ecumenism for Christianity defined in detail, did not begin with Vatican II. In a sense, it is the long story of the Eastern Orthodox church to embrace estranged communions as beneficiaries of a common gift, and simultaneously to guard against promiscuous union with them, in a pattern very similar to what has only lately been expressed by Vatican II. The history of the relationship between Eastern Orthodoxy and the Oriental Orthodox churches is a case in point. Likewise, the Eastern Orthodox have been leaders in the Interfaith movement, and some Orthodox patriarchs enlisted their communions as charter members of the World Council of Churches; at the same time, the Orthodox have been official non-participants in any redefinition of the Christian faith toward a reduced, minimal, anti-dogmatic and anti-traditional, pan-christianity. Christianity, for the Eastern Orthodox, is simply the Church; and the Church is simply Orthodoxy in the sense expressed by Holy Tradition - nothing less, and nothing else. Therefore, while Orthodox ecumenism is "open to dialogue with the devil himself", the goal is to reconcile all non-Orthodox back into Orthodoxy.

One way to observe the attitude of the Orthodox Church towards non-Orthodox is to see how they receive new members from other faiths. Non-Christians, such as Buddhists or atheists, who wish to become Orthodox Christians are accepted through the sacraments of baptism and chrismation. Protestants and Roman Catholics are often received through only chrismation, provided they had received a trinitarian baptism. Also Protestants and Roman Catholics are often referred to as "heterodox", which simply means "other believing", rather than as heretics ("other-choosing"), implying that they did not wilfully reject the Church.

The Catholic initiative: the church at odds with itself

For Christian dogmatists, there are two obstacles to the realization of the goal of unity. Some might think it ironic, that the first obstacle to the full unity of dogmatic Christianity is religious pluralism, which to some extent has goals that are antithetical to dogmatic ecumenism. This is not to say that dogmatists can never be practical and principled pluralists; however, the ultimate aim of dogmatic ecumenism cannot be reconciled with pluralism as an ideal and permanent state of affairs. This highlights the second obstacle to the realization of Christian unity, where what is meant by Christianity in its fullest sense is defined, in the case of Catholicism defined very elaborately, by certain positive doctrinal limitations. The doctrinal definitions themselves place insurmountable barriers against union on a basis which contradicts those definitions.

Until the Second Vatican Ecumenical Council, the relationship between estranged Christian traditions was basically in deadlock because of the intransigence of the Roman Catholic Church with regard to every point of division between itself and differing dogmatic Christian Churches. The traditional view of Roman Catholicism was that "there is no salvation outside the [Catholic] Church". To be sure, this intransigence works both ways, and as a result, ecumenism prior to this important council was only different by degrees from evangelization of the heathen. However, Vatican II initiated a new era in the serious pursuit of unity between diverse dogmatic traditions. This new initiative of ecumenism embraces religious pluralism as compatible with the ultimate aim of Catholic ecumenism, and simultaneously distances itself from pluralism as the ideal state of Christian unity. In papal encyclicals produced under two post-Vatican II pontifs, this new ecumenism is outlined in the first place definitively, and in the second, very practically:

The ultimate objective toward which these documents direct the Catholic ecumenical task, is nothing other than a complete, conscious communion of all Christians, indeed, of all mankind, in a single faith and one Christian Church, beginning with a conversion of the Catholic people. Ecumenism is essentially, catholic renewal.
"6. Every renewal of the Church is essentially grounded in an increase of fidelity to her own calling. Undoubtedly this is the basis of the movement toward unity..." (UR)
"The unity of all divided humanity is the will of God. For this reason he sent his Son, so that by dying and rising for us he might bestow on us the Spirit of love. On the eve of his sacrifice on the Cross, Jesus himself prayed to the Father for his disciples and for all those who believe in him, that they might be one, a living communion. This is the basis not only of the duty, but also of the responsibility before God and his plan, which falls to those who through Baptism become members of the Body of Christ, a Body in which the fullness of reconciliation and communion must be made present." (UUS)

At the same time, the pursuit of renewal is not compatible with a complacent settling into the very patterns of sin that must be removed before renewal can take place.
"In a corresponding way, there is an increased sense of the need for repentance: an awareness of certain exclusions which seriously harm fraternal charity, of certain refusals to forgive, of a certain pride, of an unevangelical insistence on condemning the "other side", of a disdain born of an unhealthy presumption." (UUS)
7. There can be no ecumenism worthy of the name without a change of heart. For it is from renewal of the inner life of our minds, from self-denial and an unstinted love that desires of unity take their rise and develop in a mature way ... The words of St. John hold good about sins against unity: "If we say we have not sinned, we make him a liar, and his word is not in us". So we humbly beg pardon of God and of our separated brethren, just as we forgive them that trespass against us." (UR)

Therefore, ecumenism expresses a central concern of the whole Christian life.
"How is it possible to remain divided, if we have been "buried" through Baptism in the Lord's death, in the very act by which God, through the death of his Son, has broken down the walls of division? Division "openly contradicts the will of Christ, provides a stumbling block to the world, and inflicts damage on the most holy cause of proclaiming the Good News to every creature". (UUS quoting UR)

In the pursuit of this ultimate objective, it is necessary to reverse past patterns of hostility, and place the Church in the service of those who are alienated from it. This service cannot paradoxically aim at the destruction of enemies through a deceitful conquest by flattery, but must sincerely desire their benefit in terms that can be immediately understood as such without first requiring the reconciliation of the enemy. Thus, there is compatibility at least in principle, between religious pluralism, and the ultimate aim of full agreement in the faith, as long as the principle of pluralism to which the Church adheres is not a contradiction of fidelity to her own calling, but in fact, an expression of it. Therefore, Catholic ecumenism depicts itself as the attempt of the Catholic church to repair a conflict within itself.

Protestantism: The church in search of itself

Protestant Christianity is a wilderness experience. Aware that it cannot on its own attain to what it envisions, it is awed by both the apparent absurdity and the unshakability of its conviction, concerning what Protestantism claims to be in relation to the rest of Christendom. This is especially true where Protestantism continues to hold a view of itself as the true correction of catholic orthodoxy in principle, with the key to both faithfulness to the gospel and genuine spiritual union. Protestantism of this classical kind is like the possessor of a key for which the door cannot be found, and which non-Protestants are convinced has never existed. This community views itself in relation to the Catholic interpretation of history as a world apart. Catholicism and Protestantism have lived parallel to one another, as though they are antimatter counterparts, constantly threatened by the other's proximity. Both worlds, it has seemed certain, would surely be destroyed if they could occupy precisely the same space at precisely the same time — therefore, as if by an inexorable law of the cosmos, they have been prevented from doing so. Viewing one another across an unbridgeable threshold, Roman Catholics and classical Protestants are gripped by mutual fascination and disdain, each the bane of the other's existence.

To a great extent, dogmatic Protestantism, the Protestantism of the Reformation, has been marginalized by both the Ecumenical Movement and the Interfaith Movement, and is hardly a factor in any major scheme of ecumenism. Instead, the very institutions which have been instruments of the humiliation of Protestant orthodoxy are viewed by Catholics and Orthodox as the prime candidates for true ecumenism. While many of these institutions maintain historical identification with the doctrinal statements that have defined their unique development, they do so without commitment to them as actual organs for the definition of Christian faith. This widely representative, liberal Protestantism has greeted Vatican II as a positive sign that all of Christendom is on the path toward joining liberal Protestantism in setting aside differences to gather all Christians for love's sake, onto the ever-shrinking island of essential Christianity. At the same time, the liberal Protestant ecumenists are cautious, in case Vatican II is a false face disguising an unreformed dogmatic spirit. Classical Protestants are skeptical about whether any ecumenical union with liberal Protestantism can ultimately be meaningful, or even possible - unless nails without a point can bind planks without substance into an edifice without structure, and someone can still call this a home.

That Protestantism with whom no one seriously seeks reconciliation, which continues to profess Christ in agreement with the ecumenical creeds, even in the face of death, and confesses that salvation is not ordinarily found outside of the visible church, has always seen as the most noble of all ambitions, the goal of unity among all Christians in the truth. But it is turned more skeptical of Catholic and Orthodox ecumenical initiatives, that are engaged in dialogue on the principles of the Reformation, with parties which no longer defend those principles. Consequently, Ut unum sint is distrusted not because it sounds hostile, but because it sounds so friendly. It enters easily in the Protestant ear, as though it were issued by its own breath — and only after listening enchanted for a while, are Protestants startled awake by signature sentences to the recognition that such comfortable words have been spoken by an unconverted enemy. Dogmatic Protestantism will not look for unity to come over the wall — it must come through the door, applying the key of unhidden Scripture, or the offerer of unity will be distrusted as a thief and a murderer through every point of his approach. As for Orthodoxy, by which it was fascinated at first, now confessing Protestantism grows weary of the Eastern inability to discern the difference between culture and dogma, and sees little hope of union so long as the East continues to promote mere eastern-ness as its point of departure and first point of pride. Therefore, the ecumenism of Protestant orthodoxy continues to be an expression of the self-frustrated quest for self-realization, for true Reformation, when "Protestant" will at long last no longer be its name.

Signs

Leaders of Catholic, Eastern Orthodox, and Protestant ecumenism. Ecumenical initiatives and documents; etc.

Catholic and Orthodox bishops in North America are engaged in an ongoing dialogue. They are meeting together periodically as the "North American Orthodox-Catholic Theological Consultation". It has been meeting semiannually since it was founded in 1965 under the auspices of the Bishops’ Committee for Ecumenical and Interreligious Affairs of the United States Conference of Catholic Bishops and the Standing Conference of Canonical Orthodox Bishops in the Americas (SCOBA). The Canadian Conference of Catholic Bishops officially joined the Consultation as a sponsor in 1997. The Consultation works in tandem with the Joint Committee of Orthodox and Catholic Bishops which has been meeting annually since 1981. Since 1999 the Consultation has been discussing the filioque clause, with the hope of eventually reaching an agreed joint statement.

The original anathemas (excommunications) that mark the "official" Great Schism of 1054 between Catholics and Orthodox were mutually revoked in 1965 by the Pope and the Patriarch of Constantinople. But just as the original schism developed over time rather than erupting overnight, reconciliation is proceeding slowly.

Some protestants who are continuing their search for the 'original' early church are finding their way back to either Catholicism or Orthodoxy. In the 1970s, the Evangelical Orthodox Church was formed by a group of Protestants based on their reading of the Bible and church history. Led by Peter Gilquist, most of them joined the Antiochian Orthodox Church in the 1980s, although a few bishops and their parishes remained independent at that time. A handful of EOC parishes joined the Orthodox Church in America in 2002. Another protestant group that has made itself "look" more Orthodox without officially becoming Orthodox is an offshoot of the Holy Order of MANS.