The Epistle to the Romans is a commentary by Swiss theologian Karl Barth on the New Testament Epistle to the Romans. First written in 1919, and later modified in 1922, Epistle to the Romans is significant as Barth's first major work, defined by his reaction against German Protestant Liberalism. Protestant Liberal theology played a significant role in the rise of German nationalism prior to World War I, leading to Barth's disillusionment and attempts to restructure Protestant theology. This work, like many of his others, emphasizes the saving grace of God and the insufficiency of human understanding to define Him.