The Proper Distinction Between Law and Gospel by C. F. W. Walther (1811-1887) is a seminal work of American Lutheran theology. A collection of 39 lectures given by Walther during 1884 and 1885, it is widely taught in Lutheran college- and seminary-level theology courses.

In classic Lutheran theology, “Law” is used to denote those parts of Scripture that reveal God’s demands on humanity, while the “Gospel” reveals the gracious and free salvation earned and given by Jesus.

Like Martin Luther before him, Walther argues that failing to properly distinguish Law and Gospel can lead Christian theology in unwanted directions. Specifically, it drives people to seek salvation in their own efforts and works rather than in Christ’s. That’s not only bad for people—for no one is blameless before divine Law—but it also robs Jesus of the glory due him as Redeemer.

Many of the particular theological movements and trends Walther uses as negative examples have disappeared. Likewise, the denominational theologies he critiques have changed since 1885. Finally, his rhetorical tone might sometimes strike contemporary readers as unnecessarily harsh.

Still, Walther’s core theological agenda has worn well over time. He centers his lectures on 25 theses, nearly all of which remain helpful guides for Christian teaching and preaching. He distills decades of personal and pastoral experience into an overall argument that seeks to give Christ his proper glory as our savior and that seeks to comfort sinners by leading them only to Christ.

Walther addressed his lectures to pastors and seminary students, so he spends a lot of time discussing the Lutheran confessional documents and writings from Luther himself. Personally, I wish he’d spent more time working through his scriptural citations, which are often quite good. At the same time, the material from Luther is always good and helps to show Law and Gospel at work in real situations.