This chapter outlines the purpose of the book and sketches out the sociological framework which holds our study. The purpose of this study is first to describe hundreds of examples of sexual exploitation in which religion is arguably implicated in motive, opportunity, modus operandi, or organisational constraint in order to come to general conclusions about the difference between religious and secular abuse, and about differences between religions. The chapter includes a clarification of terms such as abuse, exploitation and deviance to set the scene for our analysis of the cases in question. To aid us in organising the offences discussed in the book, we rely on the classical sociological theories of rule-breaking and the cases are divided according to the type of rules broken by the transgressors in question. This chapter also introduces our analytical tools as we distinguish between four types of deviance understood as rule-breaking: criminal; general; occupational; religious deviance. This chapter provides an overview of the subject and poses the key question of the role of religion in facilitating sexual transgression.