This study seeks to demonstrate that exorcism/deliverance ministry is an innately enthusiastic practice utilizing John Knox's classic study of Christian enthusiasm. The twentieth century provides an ideal arena for such a study since it frames a complete lifecycle for this rite from its infancy during the early decades, through its heyday in the 1970s and 80s, on to creeping routinisation by the end of the century. Two enthusiastic settings, Charismatic and Evangelical Fundamentalist, are identified and examined as the environment in which two related streams of exorcism/deliverance ministry was practiced. Finally, enthusiastic Sacramentalist exorcism is considered in order to establish the thesis that enthusiastic settings provide a conducive atmosphere for the emergence and practice of exorcism/deliverance ministry. Attention is paid to historical factors within the Charismatic and Evangelical Fundamentalist streams that underlie the development of this rite. As a result important secondary insights are gained into the tidal nature of enthusiastic movements, the role of itinerant preachers in the propagation of enthusiasm, the routinisation of enthusiastic practices and the manner in which enthusiasm overcomes institutional denominational boundaries. The study provides the foundation for future investigation of the manner in which enthusiastic experience is presented for apologetic purposes, the relationship between exorcism/deliverance ministry and millenarianism and the practice of this rite within non-Western churches.