Mennonites have claimed to be a “third-way” movement, neither Catholic nor Protestant. Yet we descend from the Protestant Reformation. Anabaptism emerged from the religious and political protest Martin Luther started by nailing 95 statements of dispute with Catholicism to a church door at Wittenburg, Germany, in 1517.

This year’s 500th anniversary of Luther’s epic act means more to us than a turning point of history. It is a spiritual milestone that can strengthen our unique Anabaptist identity while increasing our appreciation for the heritage we share with other branches of the Christian family.

That relationship began in conflict, as both Catholics and Protestants persecuted the Anabaptists. Though Pope Leo X denounced Luther as a wild boar in the Lord’s vineyard and Luther burned the pope’s decree condemning him, by 1525 Catholics and Lutherans could agree: The rebaptizers ought to be killed.

The Anabaptists were heretics in the eyes of both because they insisted faith was a personal choice, separate from the rule of the state. Catholics and reformers alike assumed the church encompassed all of society. The church functioned as an arm of the government. The “magisterial” reformers who broke with Rome could imagine no other way: The principle of cuius regio, eius religio — whose realm, his religion — allowed each German prince in the Reformation to decide which version of Christianity his people would follow. To make baptism an adult decision, dividing the people into church members and outsiders, would destroy the bonds that held society together. Anabaptism invited anarchy.

Five centuries of history have vindicated the Anabaptists. Both church and state benefit by severing religion from civil power. Disestablishment liberates the church to fulfill its mission. It makes democratic governments and pluralist, tolerant societies possible.

But Christendom thinking is far from dead. Methodist Bishop William H. Willimon writes in the foreword to J. Denny Weaver’s Becoming Anabaptist, first published in 1987 and updated in 2005, that today’s Anabaptists are “among the few American Christians who can look at the United States of America and the body of Christ and tell the difference.”

Though Mennonites may take pride in identifying their Anabaptist ancestors as founders of religious freedom, the Reformation’s quincentennial should be an occasion for humility and ecumenical relationship. Today’s descendants of the radical reformers and their long-ago persecutors have grown to appreciate each other’s unique spiritual gifts. In 2010 the Lutheran World Federation officially apologized for the persecution of Anabaptists, and Mennonite World Conference granted forgiveness.

Reconciliation and learning continue. On Feb. 8-14 in Germany, Catholic, Lutheran and Mennonite representatives will hold the fifth and final meeting of the International Trilateral Dialogue Commission. After last year’s session in Colombia, German Mennonite theologian Fernando Enns commented that he had anticipated a Mennonite “moment of glory” when discussion turned to the topic of baptism. Yet he was humbled by an Indian Lutheran’s ideas on costly discipleship and by a French Catholic’s call to evangelism as a fruit of baptism. Enns felt it was right “to acknowledge each other’s baptisms as authentic commitments to witness to the peace of Christ, together.”

Today, adult- and infant-baptizing Christians respect rather than condemn each other. Anabaptists know the Radical Reformation wouldn’t have happened without Luther’s bold challenge to tradition.