The doctrine of the Church was contentious as Lutherans argued for the scriptural catholicity of their churches, which embraced the Reformation over against Roman Catholic claims to be the one, holy, catholic, and apostolic church confessed in the creeds. Distinguishing between visibility and invisibility as aspects of the same church, Gerhard discusses whether the church can err and defines the true marks of the Church.This volume also covers much more than just the doctrine of the Church. It deals with mission, miracles, prophecy, the curious case of 'Pope Joan,' and the corruptions of the papacy in the centuries leading up to Gerhard's time.