How could the emerging Turkish Protestant movement best be explained? At the outset of this project, any given answer to that question was superficial or otherwise unsatisfactory. There was also a dearth of literature on the topic; however, more extensive reading led to a tentative thesis that an interplay of four factors—religious freedom, missionary activity, religious conversion, and plausibility structure—could constitute a credible explanation for the movement. Delimitations and limitations regarding the investigation of the thesis are then detailed, crucial terms and concepts are defined, underlying assumptions are discussed, the method is described, the proposed theoretical and practical significance of the study is declared, and the route and rationale for the subsequent chapters are disclosed.