Ecumenism has its roots in several religious groups that crossed denominational barriers in the mid-nineteenth century. These groups include the Evangelical Alliance, founded in England in 1846. The American branch of the same was formed by Phillip Schaff in 1867. Others that crossed denominational barriers were the Young Men's Christian Association (1844), the Young Women's Christian Association (1884), and the Christian Endeavor Society (1881). Composed of larger Protestant denominations, the Federal Council of the Churches of Christ was organized in 1908 and sought to represent Protestant opinions on religious and social matters. In addition, the movement known as Church Reunion in Great Britain and as Christian Union (1910) in the United States was attempting to achieve a creed behind which all Christians could unite.
Despite these historical precursors, the movement took flight with the 1910 World Missionary Conference in Edinburgh. That movement spawned four seminal ideas, establishing a set of interfaith priorities going forward. These ideas included:
Common Service: The Life and Work Movement, whose inaugural movement occurred in Stockholm in 1925, led to interchurch aid for the victims of war, poverty, oppression, and natural disasters. In addition, the churches were called to oppose economic and social injustice, including racism and sexism.
Common Fellowship: The first world conference for church unity was part of the Faith and Order movement. The conference was in Lausanne in 1927.
Common Witness: Concerns over cooperative mission and evangelism were voiced in the International Missionary Council, first held in Jerusalem in 1928. Here the priority was interfaith relations, a priority still in the forefront today.
Common Renewal: This final element shows that ecumenism is not some feel-good call for democratic tolerance or simple matters of interchurch cooperation. The stress is not merely on Christians getting along, but that churches be renewed and transformed to the point where they are open to the gifts of other religions.
Christian ecumenism cannot be confused with interfaith pluralism. Pluralism claims that faiths with mutually exclusive doctrines are equally valid. This view emphasizes the elements common to various religions. Ecumenism encourages dialogue between faiths but does not intend to reconcile their adherents into some religious unity. Rather, ecumenism seeks mutual respect across faiths, not to mention toleration for other views.
The World Council of Churches has met periodically since 1948. During that time, the Eastern Orthodox Church, Roman Catholics, and Pentecostalists made the council representative of various forms of Christianity. But the Council did not embrace Fundamentalism. Its embrace of liberation movements, including Liberation Theology, was not without controversy.