The rule of faith was a summary of apostolic preaching and teaching made by writers of the early Christian centuries. As such it carries great importance for what the early church considered basic to its being and identity. It was not a fixed text, like a creed, but varied in wording and content according to circumstances. Yet, despite this flexibility and diversity, there is a clear Christ-centered, Trinitarian core at the heart of the rule shared by the early apostolic churches. In this short guide, Everett Ferguson introduces readers to the primary sources of our knowledge of the rule, the variety of ways in which ancient Christian authors spoke of the rule, and different scholarly attempts to interpret this ancient evidence. Ferguson argues that statements of the rule of faith were used to instruct new or potential converts, to combat false teachings, and to provide a framework for interpreting the Scriptures. He maintains that the rule retains considerable importance for churches of the twenty-first century. ""When paging through this book, my immediate reaction was: why was it not written earlier? . . . There is no better candidate to produce this book than Ferguson . . . [who] is well known for his precision of textual references and mature judgment for pointing out the doctrinal and pastoral relevance of the topics he treats. This book must be possessed by all students studying . . . questions concerning the early history of the New Testament canon and biblical hermeneutics."" --Father Denis Farkasfalvy, OCist, University of Dallas ""Can the story of Scripture, the preaching and teaching of the apostles, be summed up in a way that can be passed from one generation to another? And how are Christians to distinguish between varying truth-claims? With the ease and depth of a master craftsman, Ferguson guides us through the regula fidei of the early Church to find an answer. Placing The Rule of Faith as a necessary companion to the well-known creeds, Ferguson brings to life again the vital truth-claims of early Christianity."" --George Kalantzis, Professor of Theology, Director, The Wheaton Center for Early Christian Studies, Wheaton College "" The Rule of Faith is an essential guide to the central beliefs of the ancient church, and Ferguson is a most trustworthy guide to its early history and development. This volume provides a collection of the most relevant primary texts and expert analysis by one of our most distinguished scholars of Christian origins . . . A splendid achievement!"" --David G. Hunter, Cottrill-Rolfes Chair of Catholic Studies, University of Kentucky Everett Ferguson is Distinguished Scholar in Residence at Abilene Christian University. He was editor of The Encyclopedia of Early Christianity (2nd edition 1997) and is author of many works including Early Christians Speak (2 volumes 1999, 2002); Backgrounds of Early Christianity (3rd ed., 2003); Inheriting Wisdom: Readings for Today from Ancient Christian Writers (2004); Church History, vol. 1: From Christ to Pre-Reformation (2005); and Baptism in the Early Church: History, Theology, and Liturgy in the First Five Centuries (2009). Ferguson received the "Distinguished Service Award" from the North American Patristics Society (2008) and the "Vestigia Award for Excellence in Early Christian Studies and Service to the Church" from the Wheaton Center for Early Christian Studies (2020).