Throughout his career, Martin Luther preached regularly. Perhaps because there is so much of it, a large portion of the extant sermon material has not been explored by scholars. However, Luther's most famous sermons, the Invocavit Sermons, are frequently quoted, discussed in every comprehensive Reformation history, and preserved in many important English collections of Luther discourse. These sermons and the situation that surrounded them continue to be crucial not only for understanding Luther's rhetoric, but for appreciating the positions and strategies of Luther's opponents. This book provides a detailed analysis of the organization, strategies, and style of Luther's Invocavit Sermons and explores how Luther's arguments functioned logically and psychologically. The author provides historical and theological background to the sermons, explains rhetorical analysis and its contributions to scholarship, and offers careful and informative commentary on each sermon. From this analysis, readers will discover a clearer picture of why Luther's preaching was so compelling.