This introduction presents an overview of key concepts discussed in the subsequent chapters of the book. The book focuses on how slavery was embedded in and constitutive of early Christian religious thought, while acknowledging that the historical context is fragmentary and biased at best. The aim of the book is to examine more closely how the discourse of slavery—doulology—functioned in the shaping of early Christian religious thought. Doulology refers to that enunciative process in which slavery and mastery operate together as a concept "to think/communicate with"—in this process, knowledge and behaviors are produced, reproduced, structured, and distributed in such a way as to establish subjects in/and positions of authority and subjugation, agency and compulsion, ownership and worth, honor and humiliation, discipline and reward/punishment, and captivity and freedom. The book is meant to be neither an exhaustive nor a conventional analysis of slavery in early Christian literature.