The earliest Christian writings are filled with stories of spirit possession and exorcism, which were crucial for the activity of the historical Jesus and for the practice of his earliest followers. Possession, besides being a harmful event that should be exorcized, can also have a positive role in many cultures. Often it helps individuals and groups to reflect on and reshape their identity, to plan their moral actions, and to remember in a most vivid way their past. This book illustrates some of the major ways in which a critical aspect of spirit possession can emerge in texts of the early Christ movement. It begins with a reading of some well-known texts in the light of a more sophisticated notion of spirit possession, which emphasizes the cultural and religious productivity inscribed in it as well as the significance of its performative nature. The book continues by looking at the fundamental role played by spirit possession in the religious experience of Paul and of his Christ groups, and the social and ethical functions of the religious experience of possession in the Pauline groups. In conclusion, when reviewing insights drawn from anthropological literature, the book attempts to treat the “spirits” involved in cases of possession seriously and not merely as mythical and metaphorical representations.