A worldview of "spiritual warfare" is widely held among charismatics and Pentecostals, but it has been criticized for producing paranoia and denying personal responsibility. It is less well known that the term was first used in print around 1970 by Anglican charismatics. What did it mean to them then, and what are the practical effects of their worldview? Should we now be adopting a more sophisticated ontology of evil, such as Nigel Wright's "non-ontological realist" view or Amos Yong's "apophatic theology" of the demonic, rather than the traditional one that Satan and demons are real ontological entities? This practical theological study begins with a study of Anglican charismatic pioneers, and an in-depth case study of a charismatic Anglican congregation, before grappling with the ontological question in dialogue with Wright (together with Barth and Walter Wink), Yong, and Gregory Boyd. A fresh engagement with the biblical texts then argues for a positive, realist ontology for rebellious demonic powers and presents a Trinitarian model of spiritual warfare praxis that emphasizes personal responsibility and promotes freedom from fear.