This book recounts, explains, and treats critically the 20th century American battles on the doctrine of the "third use" of the Law: the Law as a guide, teaching Christians what they should and should not do to lead God-pleasing lives. The author examines the key theologians in this debate and their positions, offers insights into the main issues, and seeks to present a Biblical and Lutheran understanding of the role of the Law in the Christian's life. The book touches on classic points of discussion in 20th century American theology, such as scriptural authority, theological method, doctrine of the Law and Gospel, and the impact made by existentialism.