The book explores the theme of spiritual warfare in the New Testament and the ongoing role of the church in the cosmic battle between good and evil. It begins by analyzing the theological foundations of spiritual combat, emphasizing that the church is not only a passive entity but an active participant in the cosmic struggle, empowered by Christ's victory. The text examines various aspects of this warfare, including the armor of God, the authority to bind and loose, and the role of the Holy Spirit in empowering believers for spiritual battle.

Throughout the chapters, the book addresses key New Testament teachings on the believer's role in spiritual warfare, referencing passages from Ephesians, Romans, Matthew, and Revelation. The apostle Paul's letters are a central focus, particularly in the context of perseverance, the power of the Word of God, and the victory secured by Christ through His death and resurrection. Historical analysis is integrated to show how early church fathers, medieval theologians, and Reformation figures understood the role of the church in spiritual combat, particularly in relation to heresies, persecution, and the expanding mission of the gospel.