2023 Reprint of the 1957 Fourth U.S. Edition. Abridged edition by Theodore Graebner. Full facsimile of the original edition and not reproduced with Optical Recognition Software. This work is considered Luther's most comprehensive work on justification by faith. Luther's fundamental belief in justification by faith was formed in large part by his interpretation of Galatians. Combined with the passion and faith expressed in these lectures, the biblical foundation for the crucial doctrine of justification is underscored and expressed for all Protestants. The commentary is also a historical document, a recording of a professor in a classroom in 1531 from July to December of that year, which expresses the Reformer's commitment to the good news of Jesus' death in the sinner's place, challenging the reader/hearer to compare St. Paul's theology with what he or she hears in the church today.