First, I am indebted to my wife Sara and my daughters, Maria and Olivia, who perservered with me through three years of research and writing. Second, I thank Stan DeKoven and the leaders of Vision International Education Services, who provided me opportunities for first-hand experience of the Pentecostal-Charismatic movements worldwide. Third, I thank the faculty of Oxford Graduate School who taught me the imperative of research and the dynamics of religion-society interface. Fourth, I thank my friend and colleague David Richardson for consistently challenging my scientific and religious presuppositions. Fifth, I thank my friends and colleagues David Ward, Wes Weber, and Brian Dew, who engaged with me in countless hours of theological discourse. Finally, I thank Professor Ernst Conradie, who advised me in person on more than one occasion at Princeton, carefully edited and critiqued my work, and patiently saw this thesis through to the end. To all those mentioned and to those not mentioned but should be, thank you.