Book excerpt: This book offers a creative and illuminating discussion of Protestant theology. Veteran teacher Phillip Cary explains how Luther's theology arose from the Christian tradition, particularly from the spirituality of Augustine. Luther departed from the Augustinian tradition and inaugurated distinctively Protestant theology when he identified the gospel that gives us Christ as its key concept. More than any other theologian, Luther succeeds in carrying out the Protestant intention of putting faith in the gospel of Christ alone. Cary also explores the consequences of Luther's teachings as they unfold in the history of Protestantism.