The biblical pattern for pastoral ministry derives from both testaments of the Bible. Deviations from that pattern crept into the church during the second century A.D., and continued, becoming increasingly severe into the Medieval period of the church. Nevertheless, isolated groups continued their efforts to follow the biblical pattern. These included Chrysostom and Augustine in the early church and the Paulicans, Cathari, Albigenses, and Waldenses during the Medieval period. The Reformation period witnessed a broader return to the biblical pattern through the magisterial reformation of Luther, Calvin, and others and through the Anabaptist reformation. During the Modern period, Puritan leaders such as Baxter, Perkins, and Edwards have led a return to biblical principles in pastoral ministry. Bridges, Morgan, and Allen were nineteenth century examples of biblical ministers. The late twentieth century has produced others, including Lloyd-Jones, Adams, and MacArthur.