
Peace churches are Christian churches, groups or communities advocating Christian pacifism or Biblical nonresistance. The term historic peace churches refers specifically only to three church groups among pacifist churches—Church of the Brethren; Religious Society of Friends (Quakers); and Mennonites, including the Amish, Old Order Mennonite, and Conservative Mennonites—and has been used since the first conference of the peace churches in Kansas in 1935.

The Amish are a group of traditionalist Christian church fellowships with Swiss German and Alsatian Anabaptist origins. They are closely related to, but a distinct branch off from, Mennonite churches. The Amish are known for simple living, plain dress, Christian pacifism, and are slower to adopt many conveniences of modern technology, with a view to not interrupting family time, nor replacing face-to-face conversations whenever possible.

The Brethren Church is an Anabaptist Christian denomination with roots in and one of several groups that trace its origins back to the Schwarzenau Brethren of Germany.

The Bruderhof is a Christian movement that was founded in Germany in 1920 by Eberhard Arnold. The movement has communities in the United States, the United Kingdom, Germany, Austria, Paraguay, and Australia.

The Church of the Brethren is a Christian denomination with origins in the Schwarzenau Brethren that was organized in 1708 by Alexander Mack in Schwarzenau, Germany, as a melding of the Radical Pietist and Anabaptist movements. The denomination holds the New Testament as its only creed. Historically, the church has taken a strong stance for nonresistance or pacifism—it is one of the three historic peace churches, alongside the Mennonites and Quakers. Distinctive practices include believers baptism by trine immersion; a threefold love feast consisting of feet washing, a fellowship meal, and communion; anointing for healing; and the holy kiss.

Charis Fellowship, known before 2018 as the Fellowship of Grace Brethren Churches, and before 1976 under the name of National Fellowship of Brethren Churches, is a theologically conservative fellowship of Brethren churches that was founded in 1939 as a conservative split from the Brethren Church. The word charis is Greek in origin, meaning “grace.” The church traces its roots back to the Schwarzenau Brethren movement of Alexander Mack, founded in 1708 in Schwarzenau, Germany.

The Harmony Society was a Christian theosophy and pietist society founded in Iptingen, Germany, in 1785. Due to religious persecution by the Lutheran Church and the government in Württemberg, the group moved to the United States, where representatives initially purchased land in Butler County, Pennsylvania. On February 15, 1805, the group of approximately 400 followers formally organized the Harmony Society, placing all their goods in common.

The Mennonite Church USA is an Anabaptist Christian denomination in the United States. Although the organization is a recent 2002 merger of the Mennonite Church and the General Conference Mennonite Church, the body has roots in the Radical Reformation of the 16th century. Total membership in Mennonite Church USA denominations decreased from about 133,000, before the merger in 1998, to a total membership of 120,381 in the Mennonite Church USA in 2001. In 2013 membership had fallen to 97,737 members in 839 congregations. In 2016 it had fallen to 78,892 members.

The Mennonite Disaster Service (MDS) is a volunteer network through which various groups within the Anabaptist tradition assist people affected by disasters in North America. The organization was founded in 1950 and was incorporated as a 501(c)(3) non-profit organization in 1993.

The Mennonites are members of certain Christian groups belonging to the church communities of Anabaptist denominations named after Menno Simons (1496–1561) of Friesland. Through his writings, Simons articulated and formalized the teachings of earlier Swiss founders. The early teachings of the Mennonites were founded on the belief in both the mission and ministry of Jesus, which the original Anabaptist followers held to with great conviction despite persecution by the various Roman Catholic and Protestant states. An early set of Mennonite beliefs was codified in the Dordrecht Confession of Faith in 1632, but the various groups do not hold to a common confession or creed. Rather than fight, the majority of these followers survived by fleeing to neighboring states where ruling families were tolerant of their belief in believer's baptism. Over the years, Mennonites have become known as one of the historic peace churches because of their commitment to pacifism.

The Moravian Church, formally called the Unitas Fratrum, known in German as the [Herrnhuter] Brüdergemeine [sic], is one of the oldest Protestant denominations in the world, dating back to the Bohemian Reformation of the 15th century and the Unity of the Brethren founded in the Kingdom of Bohemia.

Quakers, also called Friends, belong to a historically Christian denomination known formally as the Religious Society of Friends or Friends Church. Members of the various Quaker movements are all generally united by their belief in the ability of each human being to experientially access the light within, or "that of God in every one".

The River Brethren are any of certain Christian groups originating in 1770, during the Radical Pietist movement among German colonists in Pennsylvania. In the 17th century, Mennonite refugees from Switzerland had settled their homes near the Susquehanna River in the northeastern United States.

The Schwarzenau Brethren, the German Baptist Brethren, Dunkers, Dunkards, Tunkers, or simply the German Baptists, are an Anabaptist group that originally dissented from several Lutheran and Reformed churches that were officially established in some German-speaking states in western and southwestern parts of the Holy Roman Empire as a result of the Radical Pietist ferment of the late 17th and early 18th centuries.

The Schwenkfelder Church is a small American Christian body rooted in the 16th-century Protestant Reformation teachings of Caspar Schwenkfeld von Ossig (1489–1561).

The Tree of Peace Society was founded in 1984 and incorporated in New York State on October 17, 1994, as a "foreign" not-for-profit corporation. Its headquarters are located on the Akwesasne Mohawk reservation in Hogansburg, New York, which borders the provinces of Quebec and Ontario, Canada along the St. Lawrence River.

Unitarian Universalism (UU) is a liberal religion characterized by a "free and responsible search for truth and meaning". Unitarian Universalists assert no creed, but instead are unified by their shared search for spiritual growth, guided by a dynamic, "living tradition". Currently, these traditions are summarized by the Six Sources and Seven Principles of Unitarian Universalism, documents recognized by all congregations who choose to be a part of the Unitarian Universalist Association. These documents are 'living', meaning always open for revisiting and reworking. Unitarian Universalist (U.U.) congregations include many atheists, agnostics, and theists within their membership—and there are U.U. churches, fellowships, congregations, and societies all over America—as well as others around the world. The roots of Unitarian Universalism lie in liberal Christianity, specifically Unitarianism and universalism. Unitarian Universalists state that from these traditions comes a deep regard for intellectual freedom and inclusive love. Congregations and members seek inspiration and derive insight from all major world religions.