In Demonology, Peter Tan provides an in-depth exploration of the nature, hierarchy, and operations of demonic forces from a Christian perspective. Drawing upon biblical scriptures, Tan examines the origins of Satan and his cohorts, offering insights into their organizational structure and influence in the spiritual realm. The book serves as a foundational guide for believers seeking to understand and engage in spiritual warfare, emphasizing the importance of recognizing and combating demonic activities in daily life. By equipping readers with knowledge and practical strategies, Tan aims to empower individuals to overcome spiritual adversaries and live victorious lives.