The Wesleyan quadrilateral is a shorthand way that followers of John Wesley use to summarize his understanding of religious authority, The idea of the Wesleyan quadrilateral continues to be crucial to how Christians today understand and live out the gospel of Jesus Christ. Wesley’s fourfold understanding of religious authority included Scripture, tradition, reason, and experience. He considered Scripture to be unique, inspired, trustworthy, and the primary religious authority for Christian beliefs, values, and practices. In addition, Wesley appealed to tradition, reason, and experience as genuine, albeit secondary, religious authorities that helped Christians contextualize their understanding and application of biblical Christianity. It was important for John Wesley to investigate the full context of religious data as he inductively and deductively studied Scripture as well as church tradition and relevant experience–including experience that is spiritual and physical, individual and collective. This book is an incisive, concise, and clear introduction to the Wesleyan quadrilateral.