Gerhard O. Forde’s “On Being a Theologian of the Cross” is an illuminating exposition of Martin Luther’s Heidelberg Disputation (1518). He unpacks the meaning of the 28 theological theses that Luther presented before the Augustinian order, and how these theses provide the foundation of for Protestant soteriology when it comes to the contrast between Law and Gospel, the bondage of the will, and absolute sufficiency of God’s grace when it comes to salvation.
All of this is presented in terms of a contrast between what are called the “Theology of Glory” and the “Theology of the Cross.” The “Theology of Glory” is used as a catch-all for sorts of theologies that look at God and salvation from the lens of human merit and human achievement. By contrast, the “Theology of the Cross” is the type of theology that sees everything from the lens of the work of Christ on the cross. Under this theology, human works or human will give way to God’s grace as displayed on the cross, or as Paul puts it, “it is not of him who wills, nor of him who runs, but of God who shows mercy” (Romans 9:16).
The book is divided into four chapters, each of which corresponds to a section of the Heidelberg Disputation. Chapter one, “The Problem of Good Works,” focuses on theses 1-12. Its aim is to show how we cannot attain God’s favour by any works that we do. Forde points out that while we recognize the problem of bad deeds, a more subtle danger arises in the form of good deeds that we think are meritorious before God. Such deeds turn out to be deadly sins if we glory in them or rely on them for our salvation. Contrasted with such human works are the works of God, which consist in humbling ourselves before God and relying on His grace.
Chapter two, “The Problem of Will,” focuses on theses 13-18. Here, Forde discusses a common error that theologians of glory fall into, which is to ascribe salvation to an act of will. Against this such a theology is the classic Augustinian notion of the bondage of the will, which Luther brings up and defends. His point is that our will, as long as it is in bondage to sin, can only choose what is earthly, not spiritual goods (cf. Romans 8:5-8). Forde thus states that the cross itself “is the evidence that we did not choose him but that he, nevertheless, chose us (John 15:16).”
Chapter three, “The Great Divide: The Way of Glory versus the Way of the Cross” focuses on theses 19-24. Here is where Luther first explicitly uses the term “theologian of glory” and “theologian of the cross.” He argues that any proper theology must be a theology of the cross. The contrast between the two is that a theologian of glory “calls evil good and good evil,” whereas a theologian of the cross “says what a thing is.” This entails resisting any tendency to shrink back from the absolute dependence on God entailed by the Gospel and to return to some form of self-effort.
Finally, chapter four “God's Work in Us: The Righteousness of Faith,” focuses on these 25-28. Here is where Luther brings his discussion into full circle. Having eliminated all works and willpower as conditions for salvation, he lays out how it is our faith alone that puts us right before God. By faith, he teaches, God’s love reaches into us and creates what is lovely in His sight (contrasted with human love, which merely seeks what is already there that is lovely). Such individuals He counts as righteous, and they can, by grace, boast that everything has already been done for them in Christ.
The Heidelberg Disputation can be a confusing read for those who are unfamiliar with the historical background of Luther and the Reformation, and Forde does a good job of clarifying the central points of his theology as found in the document. He takes Luther's points and shows how they are still applicable to our understanding of God and salvation today. I highly recommend this book as an introduction to Luther’s thought, and to broader Protestant theology in general.