Religious beliefs--especially when tied to a powerful church-equals-state system that governs moral precepts, land ownership, taxation, and commerce--can lead to vast, bloody wars. Europe was stained red by all the fighting in the 16th and 17th centuries: bloody insurrections to stamp out the teachings of John Calvin in the Netherlands and France; the costly defeat of Catholic Spain's once invincible armada; the murder of inconvenient wives before England's King Henry VIII decided to break with Rome and establish the Church of England.

Decades and decades of war led to the establishment of U.S. Protestantism's mainline denominations during and after the Revolutionary War. Calvinism led to the Puritans; its ethic of hard work, order, democracy, and a strict adherence to Scripture now lives on within the Presbyterian Church (USA) and other, smaller Presbyterian denominations. The Episcopal Church is the American offshoot of the Anglican Church, created by Henry VIII. The autonomous Methodist Episcopal Church was constituted in 1784, at the historic Christmas Conference in Baltimore.

Infighting has remained a major and ongoing (if far less bloody) presence among U.S. denominations. People take their most deeply held beliefs seriously. And when they perceive their church to be straying from those beliefs, or when issues of the day create differences between personal conscience and denominational stance, the sense of betrayal or aloneness is strong--so strong that the only options might be to fight or split.

Slavery was such an issue for some denominations, including the Methodists. Northern Methodists opposed the practice and those in the South embraced it. In 1844, the tension led to schism, leaving two churches: the Methodist Episcopal Church and the Methodist Episcopal Church, South. (The African Methodist Episcopal Zion Church and the African Methodist Episcopal [AME] Church were set up for people of African descent prior to the mainstream Methodist split; they still exist today, using the same doctrine and system of governance as the current United Methodist Church.)

But, as the Methodists showed, schism can lead to reconciliation. In 1939, slavery had been long abolished and the two bodies, which both had assimilated into the general behaviors of American Protestantism, came together again (along with a smaller group, the Methodist Protestant Church) as the Methodist Church. As one body, however, there were still conflicts--governed by a General Conference and smaller regional conferences, one Central Conference was set up specifically for African-American Methodists who had not aligned with the all-black AME churches. That segregation ended in 1968, the same year that a union between the Methodist Church and the Evangelical United Brethren Church led to the formation of the United Methodist Church.

Slavery divided the Presbyterian Church into two as well; reunification did not happen until 1983. "Historic Principles, Conscience, and Church Government," a report issued that year, says schism, though monumentally painful, is sometimes the only way to go. "It is perhaps fair to say that no knowledgeable member or officer of the church can agree with every requirement in the 'Form of Government,' and with every position which the church takes on every issue," the report says. "Scripture is our highest authority and no church governing body may bind conscience contrary to Scripture. It can, however, interpret Scripture and require that those who disagree either submit or withdraw peaceably. Because of the right to withdraw, the individual conscience cannot be bound by actions of the church."