The volume undertakes a Catholic appreciation of Luther's theology and Lutheranism with ecumenical intent. Against the backdrop of the diverse and sometimes contradictory interpretations of Luther over the past 500 years, the author demonstrates that the core concern of Luther and his Reformation lies in the message of justification. Building on this, the central theological themes that remain contentious between Catholics and Protestants to this day are addressed: faith and works, Scripture and tradition, church and offices, sacraments. It becomes evident that a retrospective look at Luther can help overcome these doctrinal disputes. Thus, Luther and his message surprisingly emerge as a figure of ecumenism - as our "common teacher.".