In 1517, Martin Luther set off what has been called, at least since the nineteenth century, the Protestant Reformation. Can Christians of differing traditions commemorate the upcoming 500th anniversary of this event together? How do we understand and assess the Reformation today? What calls for celebration? What calls for repentance? Can the Reformation anniversary be an occasion for greater mutual understanding among Catholics, Orthodox, and Protestants? At the 2015 Pro Ecclesia annual conference for clergy and laity, meeting at the Catholic University of America in Washington, DC, an array of scholars—Catholic and Orthodox, Evangelical Lutheran and American Evangelical as well as Methodist—addressed this topic. The aim of this book is not only to collect these diverse Catholic and Evangelical perspectives but also to provide resources for all Christians, including pastors and scholars, to think and argue about the roads we have taken since 1517—as we also learn to pray with Jesus Christ "that all may be one" (John 17:21).