another house group). They had no professional clergy, no official leadership structures, no central organization, no mass meetings, and yet they grew like mad. How is this possible? How did they do it?5 But we can observe similar growth patterns in other historical movements. Steve Addison notes that by the end of John Wesley’s lifetime one in thirty English men and women had become Methodists.6 In 1776 fewer than 2 percent of Americans were Methodists. By 1850, the movement claimed the allegiance