While each congregation is at liberty to decide independently on its form of worship and other matters, Mennonites generally agree on certain points—baptism of believers only, the necessity of repentence and conversion for salvation, the refusal to bear arms and to take oaths, the rejection of worldly concerns, simplicity of dress and habits, and disapproval of marrying outside the faith. In celebrating the Lord's Supper, some branches include the rite of foot washing and the kiss of charity.
Differences in discipline and performance of church services have resulted in a division of the church into a number of branches. The Mennonite Church, whose members are sometimes known as Old Mennonites, is the original body in the United States and has the largest membership. The General Conference of the Mennonite Church of North America (1860), the next largest body, may be listed among the more liberal branches. One of the most conservative divisions is the Amish Church, which, under the leadership of Jacob Amman (late 17th cent.), broke away from the main body in Europe. The Amish are noted for their rejection of the world and most modern technology and conveniences, and have historically farmed in a traditional manner or earned a livelihood by practicing such crafts as carpentry and cabinetry. The principal Amish groups in the United States are the Old Order Amish, who do not use churches but worship in homes and conduct their services in German, and the Conservative Amish, who abide by the Dordrecht Confession of Faith but hold services in English as well as German and accept such innovations as the Sunday school. The terms "House Amish" and "Church Amish" have been used to distinguish the branches. The Amish in the United States are predominantly in Pennsylvania, Ohio, and Indiana, but Amish communities are found in more than half the states. Another conservative body is the Reformed or Herrite branch, established (1812) under the leadership of John Herr. The Church of God in Christ (1859) and the Old Order Mennonites, formed in 1870 under Jacob Wisler, are among the other branches.
Large numbers of Mennonites are found in Canada, and a number of American, Canadian, and European Mennonites have moved to colonies in Mexico and South America. Although attempts at unification have not been particularly successful, the Mennonite Central Committee, formed in 1920 as a response to famine affecting Mennonites in Russia and Ukraine, has enabled the branches to cooperate in many service and relief activities around the world. There are now over 1 million baptized members worldwide. The largest denomination in the United States is the Mennnonite Church USA.