Schism breeds schism. That was the stick with which [the] Catholic Church and civil authorities beat Luther from the beginning. By attacking the authority of the established church and flouting the authority of the established state, he was fomenting social upheaval. It was a charge to which he was particularly sensitive. He insisted that his own ideas buttressed rather than subverted authority, especially civil authority, under whose protection he had placed the Church. As early as 1525, peasants in Swabia appealed to Luther for support in their social rebellion. They based some of their most controversial demands, such as the abolition of tithes and labor service, on biblical authority. Luther offered them no comfort. "Let every person be subject to the governing authorities with fear and reverence," he quoted from the Bible while instructing rebels to lay down their arms and await their just rewards in heaven.

But Luther's ideas had a life of their own. He clashed with Erasmus over free will and with Zwingli over the Mass. Toward the end of his life he felt he was holding the floodgates against the second generation of Protestant thinkers. Time and again serious reformers tried to take one or another of his doctrines further than he was willing to go himself. The water was seeping in everywhere.

The most dangerous threat to the establishment of an orthodox Protestantism came from groups who were described, not very precisely, as Anabaptists. Anabaptist was a term of abuse. Although it identified people who practiced adult baptism—literally, "baptism again"—the label was mainly used to tar religious opponents with the brush of extremism. For more than a hundred years it defined the outcast from the Protestant fold. New ideas were branded Anabaptist to discredit them; religious enthusiasts were labeled Anabaptists to expel them. Catholics and Protestants both used the term to describe what they were not, and thereby defined what they were.

Anaptists appeared in a number of German and Swiss towns in the 1520s. Taking seriously the doctrine of justification by faith, Anabaptists argued that only believers could be members of the true church of God. Those who were not of God could not be members of his church. While Catholics, Lutherans, and Calvinists incorporated all members of society into the church, Anabaptists excluded all but true believers. As baptism was the sacrament through which entry into the church took place, Anabaptists reasoned that it was a sacrament for adults rather than infants. Although the practice was as much symbolic as substantive, it was a practice that horrified others. Infant baptism was a core doctrine for both Catholics and Protestants. It was one of only two sacraments that remained in reformed religion. It symbolized the acceptance of Christ, and without it eternal salvation was impossible. Luther, Zwingli, and Calvin agreed that infant baptism was biblical in origin and all wrote vigorously in its defense. It was a doctrine with practical import. Unbaptized infants who died could not be accepted in heaven, and infant mortality was appallingly common.

Thus the doctrine of Anabaptism posed a psychological as well as a doctrinal threat to the reformers. But the practice of adult baptism paled in significance to many of the other conclusions that religious radicals derived from the principle of sola scriptura—by the Word alone. Some groups argued the case that since true Christians were only those who had faith, all others must be cast out of the church. Those true Christians formed small separate sects. Many believed that their lives were guided by the Holy Spirit, who directed them from within. Both men and women could give testimony of revelations that appeared to them or of mystical experiences. Some went further and denied the power of civil authority over true believers. They would have nothing to do with the state, refusing to pay taxes, perform military obligations, or give oaths: "The Sword must not be used by Christians even in self-defense. Neither should Christians go to law or undertake magisterial duties." Some argued for the community of goods among believers and rejected private property. Others literally followed passages in the Old Testament that suggested polygamy and promiscuity.

Wherever they settled, the small bands of believers were persecuted to the brutal extent of the laws of heresy. Catholics burned them, Protestants drowned them, and they were stoned and clubbed out of their communities.

Although Anabaptists were never a large group within the context of the Protestant churches, they represented an alternative to mainstream views—whether Lutheran or Calvinist—that was both attractive and persistent. There was enough substance in their ideas and enough sincerity in their patient sufferings that they continued to recruit followers as they were driven from town to town, from Germany into the Swiss cities, from Switzerland into Bohemia and Hungary.

There, on the eastern edges of the Holy Roman Empire, the largest groups of Anabaptists finally settled. Although all practiced adult baptism, only some held goods in common or remained pacifist. Charismatic leaders such as Balthasar Hubmaier (1485-1528) and Jacob Hutter (d. 1536) spread Anabaptism to Moravia in southern Bohemia, where they converted a number of the nobility to their views. They procured land for their communities, which came to be known as the Moravian Brethren. The Moravian Anabaptists ultimately split on the question of pacifism when the advancing Turkish armies posed the problem starkly. Anabaptists remained a target of official persecution, and Hubmaier, Hutter, and a number of other leaders met violent deaths. But the Moravian communities were able to survive and to spread their movement throughout Hungary and Poland. Independent groups existed in England and throughout northwest Europe, where Menno Simons (1496-1561), a Dutch Anabaptist, spent his life organizing bands of followers who came to be known as Mennonites.

Source: Kishlansky, Mark, Patrick Geary, et al. Civilization in the West, Vol. 1. New York: Longman, 2003. 425-6.