Church union is the name given to a merger of two or more Christian denominations. Such unions may take on many forms, including a united church and a federation.

United churches

{{main, United and uniting churches A united church is the result of a merger of churches of various denominations. One of the first of these occurred in 1817, when

Lutheran Lutheranism is one of the largest branches of Protestantism, identifying primarily with the theology of Martin Luther, the 16th-century German monk and Protestant Reformers, reformer whose efforts to reform the theology and practice of the Cathol ...

and Reformed churches in

Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an ...

merged into the Prussian Union. The nineteenth century saw a number of unions between churches of the same tradition. For example, the United Secession Church in Scotland was formed in 1820 by a union of various churches which had seceded from the established

Church of Scotland The Church of Scotland ( sco, The Kirk o Scotland; gd, Eaglais na h-Alba) is the national church in Scotland. The Church of Scotland was principally shaped by John Knox, in the Reformation of 1560, when it split from the Catholic Church ...

. All these were

Presbyterian Presbyterianism is a part of the Reformed tradition within Protestantism that broke from the Roman Catholic Church in Scotland by John Knox, who was a priest at St. Giles Cathedral (Church of Scotland). Presbyterian churches derive their nam ...

in both doctrine and practice. In the twentieth century many churches merged as a result of the

Ecumenical movement Ecumenism (), also spelled oecumenism, is the concept and principle that Christians who belong to different Christian denominations should work together to develop closer relationships among their churches and promote Christian unity. The adjec ...

. One of the earliest such unions was in 1925, and formed the

United Church of Canada The United Church of Canada (french: link=no, Église unie du Canada) is a mainline Protestant denomination that is the largest Protestant Christian denomination in Canada and the second largest Canadian Christian denomination after the Catholi ...

. Other examples include like-minded bodies with a common theological history such as the

United Methodist Church The United Methodist Church (UMC) is a worldwide mainline Protestant denomination based in the United States, and a major part of Methodism. In the 19th century, its main predecessor, the Methodist Episcopal Church, was a leader in evangelic ...

– a merger of the Evangelical United Brethren Church and the Methodist Church in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

Federation

A federation is a less centralized union. One example includes the

Churches of New South Wales, Victoria, Queensland, South Australia, Tasmania and Western Australia, which joined together to form the Presbyterian Church of Australia on July 24, 1901. The structure was similar to the

Federation A federation (also known as a federal state) is a political entity characterized by a union of partially self-governing provinces, states, or other regions under a central federal government ( federalism). In a federation, the self-govern ...

which formed the

Commonwealth of Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...

on January 1 of that same year. In his inaugural moderatorial address, John Meiklejohn made it clear that the ecclesiastical union consciously reflected the political union of the Australian colonies: "We have, by forming this Assembly, formed a Court whose jurisdiction is, as regards territory, equal to, and coterminous with that of the Federal Parliament, and like it, is representative in its character." This union linked churches of the same denomination in different locations into one body without forming a monolithic national church. The individual state churches also kept their individual identities, rights, and privileges.

The Uniates and the Edinoverie

The term "union" (e.g., the Union of Brest of 1596) is also used for the arrangement when a group of Orthodox Christians enters communion with the Catholic Church's Pope of Rome, while wishing to maintain their Eastern rites. Such groups are known generically as

Eastern Catholic Churches The Eastern Catholic Churches or Oriental Catholic Churches, also called the Eastern-Rite Catholic Churches, Eastern Rite Catholicism, or simply the Eastern Churches, are 23 Eastern Christian autonomous ('' sui iuris'') particular churches of t ...

. Their adherents are occasionally referred to as ''uniates''. In a somewhat parallel way, but on a much smaller scale,

Russian Orthodox Church , native_name_lang = ru , image = Moscow July 2011-7a.jpg , imagewidth = , alt = , caption = Cathedral of Christ the Saviour in Moscow, Russia , abbreviation = ROC , type ...

has integrated certain

Old Believer Old Believers or Old Ritualists, ''starovery'' or ''staroobryadtsy'' are Eastern Orthodox Christians who maintain the liturgical and ritual practices of the Russian Orthodox Church as they were before the reforms of Patriarch Nikon of Moscow be ...

communities, allowing them to keep their rites while recognizing the authority of the national church. This arrangement is known as

Edinoverie Edinoverie ( rus, единове́рие, p=jɪdʲɪnɐˈvʲerʲɪjɪ, literally “coreligionism”) is an arrangement between certain Russian Old Believer communities and the official Russian Orthodox Church, whereby such communities are treated a ...

United churches

Federation

The Uniates and the Edinoverie

See also