Ecumenism and Orthodoxy

Ecumenism is, principally, dialogue between Christian groups aimed at promoting the restoration of unity among all Christians through understanding, through mutual respect and toleration, and through practical cooperation in areas of common concern, such as care for the poor, sick, and needy.
Orthodox Christians were engaged in the foundation of the ecumenical movement from its inception. The primary basis for the Orthodox role in the ecumenical movement was a statement issued by the Ecumenical Patriarchate of Constantinople in 1920 entitled "Unto All the Churches of Christ Wheresoever They Be." A number of Orthodox churches were present at the initial founding conference of the World Council of Churches, and most have continued to participate in the life of the WCC, as well as in national and regional councils of churches.

Some Orthodox Christians have criticized participation in the ecumenical movement. They believe that ecumenical witness represents a concession to the "Branch Theory," which suggests that the various divisions in Christianity all represent branches of the same Church just as the branches of a tree are all integrally part of the same living tree. Under such a model, Orthodoxy would be defined not as exclusively the one, holy, catholic, and apostolic Church, but rather as a relatively small segment of the Church: one denomination among many. (However, this understanding of ecumenism is not supported by the agreements which define ecumenical structure, most notably the Toronto Declaration.)
In the Twentieth Century particularly, some ecumenical activities have drawn sharp criticism from various voices within the Orthodox Church, particularly participation in the World Council of Churches and, in the United States, the National Council of Churches of Christ in the USA.
One of the more controversial documents drawn up in recent years pertaining to ecumenism is the Balamand Statement, an unofficial joint document of recommendation on Uniatism signed by representatives of the Orthodox Church and the Roman Catholic Church in 1993.
Recently, many of the Orthodox Churches in the United States, including the Antiochian Orthodox Christian Archdiocese of North America, the Greek Orthodox Archdiocese of America, and the Orthodox Church in America have joined a new ecumenical organization called Christian Churches Together. CCT is intended to represent a broader coalition of Christian communions, including Roman Catholics and Evangelicals (who do not participate as full members in either the WCC or NCCCUSA.)(wiki)