Countless historians have gone to great lengths to explain the Reformation through social, political, and economic causes. No doubt each of these played a role during the Reformation, and at times a significant role. Yet most fundamentally, the Reformation was a theological movement, caused by doctrinal concerns. Though political, social, and economic factors were important, observes Timothy George, “we must recognize that the Reformation was essentially a religious event; its deepest concerns, theological.” What this means, then, is that we must be “concerned with the theological self-understanding” of the Reformers.
But more can be said. Yes, the Reformation was a “religious event,” and its deepest concern was “theological.” But history is filled with religious and ethical reform movements that considered themselves theological in orientation. What distinguishes the Reformation, however, is that its deepest theological concern was the gospel itself. In other words, the Reformation was a renewed emphasis on right doctrine, and the doctrine that stood center stage was a proper understanding of the grace of God in the gospel of his Son, Christ Jesus. In part, this is what distinguished Luther from the forerunners of the Reformation. As Lindberg notes, referring to one of Luther’s early sermons, the “crux of genuine reform . . . is the proclamation of the gospel of grace alone. This requires the reform of theology and preaching but is ultimately the work of God alone.” For Luther, explains McGrath, a “reformation of morals was secondary to a reformation of doctrine.” While forerunners stressed the need for ethical reform in the papacy, Luther recognized that the real problem was a dogmatic one. The great need was theological; the “crux of genuine reform” had to do with the recovery of the gospel itself.
The Reformers believed that this gospel had been lost (or at least corrupted). Luther was convinced that Pelagianism and semiPelagianism had spread like the plague, at least at a popular level, thanks to the influence of certain strands of medieval Catholicism. As Luther’s conflict with Rome heated up, eventually erupting like a volcano, it became increasingly clear to Luther that the corruption of the gospel in his own day had resulted in the abandonment of justification sola gratia and sola fide, and vice versa. The consequences were grave. Luther warned at the start of his 1535 Galatians commentary that “if the doctrine of justification is lost, the whole of Christian doctrine is lost.” And again, “If it is lost and perishes, the whole knowledge of truth, life, and salvation is lost and perishes at the same time.” Nothing less was at stake. Therefore, apart from a rediscovery of doctrines like sola fide and the imputation of the righteousness of Christ, lasting reform would never take root. That being the case, it was undeniably obvious to Luther that his teaching, preaching, and writing had to revolve around the gospel, specifically its ramifications for justification by faith alone. As Luther wrote to Staupitz, “I teach that people should put their trust in nothing but Jesus Christ alone, not in their prayers, merits, or their own good deeds.” This one sentence, says Scott Hendrix, summarizes “the essence” of Luther’s “reforming agenda.”
Of course, Luther’s rediscovery of the gospel—which he called the “treasure of the Church”—was an experience Luther knew firsthand. Recounting his own personal durchbruch, or “breakthrough,” Luther’s testimony is powerful:
Though I lived as a monk without reproach, I felt that I was a sinner before God with an extremely disturbed conscience. I could not believe that he was placated by my satisfaction. I did not love, yes, I hated the righteous God who punishes sinners, and secretly, if not blasphemously, certainly murmuring greatly, I was angry with God, and said, “As if, indeed, it is not enough that miserable sinners, eternally lost through original sin, are crushed by every kind of calamity by the law of the Decalogue, without having God add pain to pain by the gospel and also by the gospel threatening us with his righteousness and wrath!” Thus I raged with a fierce and troubled conscience. Nevertheless, I beat importunately upon Paul at that place, most ardently desiring to know what St. Paul wanted. At last, by the mercy of God, meditating day and night, I gave heed to the context of the words, namely, “In it the righteousness of God is revealed as it is written, ‘He who through faith is righteous shall live.’” There I began to understand that the righteousness of God is that by which the righteous lives by a gift of God, namely by faith. And this is the meaning: the righteousness of God is revealed by the gospel, namely, the passive righteousness with which merciful God justifies us by faith, as it is written, “He who through faith is righteous shall live.” Here I felt that I was altogether born again and had entered paradise itself through open gates.
In light of Luther’s durchbruch, if we were to use but one word to characterize the Reformation, it might be rediscovery, that is, a rediscovery of the evangel, the gospel. It is right to conclude, then, that the Reformation was an evangelical reform at its root.
Nevertheless, even the word rediscovery assumes that the Reformers did not think they were inventing something new (contra Rome’s accusation of novelty). Indeed, they were renewing, retrieving, and reviving what they believed had been lost. This lost gospel had been taught by the biblical authors, as well as by the apostles and church fathers. And since they insisted on reform not just in externals but also in doctrine, the Reformers became characterized by the theology behind that slogan Ecclesia reformata, semper reformanda—“The church reformed, always reforming,” even if the slogan itself was a much later development.
Content taken from Reformation Theology: A Systematic Summary Edited by Matthew Barrett, ©2017. Used by permission of Crossway, a publishing ministry of Good News Publishers, Wheaton, Il 60187, www.crossway.org.
I have chosen to use the singular Reformation. However, others (even in this volume) have used the plural Reformations to refer to the diversity and plurality that existed during the sixteenth century and the multiple Reformations that took place throughout Europe. See, e.g., Carter Lind- berg, The European Reformations (Oxford: Blackwell, 1996). I agree with this observation; we can speak of a plurality of Reformations, each of which differed from one another. Nevertheless, I stick with the traditional language, using the singular, because, as this introduction reveals, a shared theological center characterized all the Reformers. It is not without justification to speak of the Reformation as a whole. While there is diversity among the Reformers, there is also unity when it comes to their common cause in restoring the gospel of grace, which is all too apparent in their united attack against Rome.
Additionally, sometimes the motive behind emphasizing a plurality of Reformations is to include the Catholic Reformation. However, from a Protestant perspective of history, it is more appropriate to label Trent a Counter-Reformation. It is no surprise that some Catholic scholars want to even get rid of the term Reformation since it “goes along too easily with the notion that a bad form of Christianity was being replaced by a good one.” John Bossy, Christianity in the West, 1400–1700 (Oxford: Oxford University Press, 1985), 91. But this is exactly what the Reformers believed to be the case—hence the need they saw for reformation. McGrath makes this point by noting Luther’s interpretation of certain forerunners of the Reformation: “For Luther, the reformation of morals and the renewal of spirituality, although of importance in themselves, were of secondary significance in relation to the reformation of Christian doctrine. Well aware of the frailty of human nature, Luther criticized both Wycliffe and Huss for confining their attacks on the papacy to its moral shortcomings, where they should have attacked the theology on which the papacy was ultimately based. For Luther, a reformation of morals was secondary to a reformation of doctrine.” Alister E. McGrath, Luther’s Theology of the Cross: Martin Luther’s Theological Breakthrough, 2nd ed. (Oxford: Wiley-Blackwell, 2011), 26.
 For example, reading through some of the most recent biographies and treatments of Reformation figures will give one a sense for how such factors coincided with the success or failure of reform. See, e.g., Scott H. Hendrix, Martin Luther: Visionary Reformer (New Haven, CT: Yale University Press, 2015); Jane Dawson, John Knox (New Haven, CT: Yale University Press, 2015); Scott M. Manetsch, Calvin’s Company of Pastors: Pastoral Care and the Emerging Reformed Church, 1536–1609, Oxford Studies in Historical Theology (Oxford: Oxford University Press, 2013).
 We must be careful not to swing the pendulum too far to the other side as well. Whit- ford reminds us that in the sixteenth century, theological beliefs heavily influenced social and political beliefs: “Because the early-modern world was not yet a secular world, the theological affected the social and political just as much and sometimes more than the narrowly defined ecclesiastical.” At the same time, Whitford recognizes that the European Reformation “was primarily a religious event driven by theological concerns.” David M. Whitford, “Studying and Writing about the Reformation,” in T&T Clark Companion to Reformation Theology, ed. David M. Whitford (London: T&T Clark, 2012), 3. Also, McGrath observes that the new trend in social history is to define and interpret the Reformation in economic and social categories, and he notes how such an approach has led some to misinterpret the Reformation, resulting in “embarrassing” conclusions. Nevertheless, he argues, “While such nonsense can now be safely disregarded, it is now beyond dispute that any attempt to make sense of the origins, the popular appeal, and the transmission of Protestantism demands careful study of the structures and institutions of contemporary society.” Alister McGrath, Christianity’s Dangerous Idea: The Protestant Reformation—A History from the Sixteenth Century to the Twenty-First (New York: HarperOne, 2007), 8.
 Timothy George, Theology of the Reformers (Nashville: Broadman, 1998), 18. McGrath likewise warns against the temptation of treating the ideas of the Reformation as a “purely social phenomenon.” Alister E. McGrath, Reformation Thought: An Introduction, 4th ed. (Oxford: Wiley-Blackwell, 2012), xv, xvi, 1.
 George, Theology of the Reformers, 18.
 Lindberg, The European Reformations, 10.
 McGrath, Luther’s Theology of the Cross, 27.
 The “essential factor which led to this schism in the first place” was “Luther’s fundamental conviction that the church of his day had lapsed into some form of Pelagianism, thus compromising the gospel, and that the church itself was not prepared to extricate itself from this situation.” Ibid. Some today will contest such a traditional view, believing Luther and Calvin to have been seriously mistaken in their understanding both of the late-medieval period and of the state of Rome in the sixteenth century as theologically and morally corrupt. Furthermore, the argument goes, the Catholic reform responded not to the Protestant Reformers but rather to pre-Reformation criticisms within the Catholic Church. In response, to label as erroneous the view that the late-medieval church was theologically mistaken is itself a theological evaluation, one that goes directly against the evaluation of the Reformers. Additionally, while we do not want to ignore the significance of dissenting voices within the Catholic Church even prior to Luther’s protest, to say that Rome was not responding to the attacks of the Protestant Reformers is off the mark, as the Council of Trent’s explicit and direct anathemas of Reformation doctrine demonstrate.
 Martin Luther, Lectures on Galatians (1535), LW 26:9.
 On the other hand, he said, “if it flourishes, everything good flourishes—religion, true worship, the glory of God, and the right knowledge of all things and of all social conditions.” Ibid., LW 26:3.
 Martin Luther, “Letter to Johann von Staupitz” (March 31, 1518), WABr 1:160.
 Hendrix, Martin Luther, 68.
 Martin Luther, “Preface to the Complete Edition of Luther’s Latin Writings,” LW 34:336– 37.
 Such a principle also applies to other Reformation doctrines, such as sola scriptura. Lindberg gives an excellent example from Luther: “Thus in the Leipzig debate (1519) over papal authority, Luther stated that papal claims to superiority are relatively recent. ‘Against them stand the history of eleven hundred years, the text of divine Scripture, and the decree of the Council of Nicea , the most sacred of all councils’ (LW 31:318).” Lindberg, The European Reformations, 5.
 From the humanist side of things, this emphasis can be seen in the motto of the Renaissance, ad fontes, “to the sources.” Many of the Reformers were influenced by humanism and thus applied this motto to the Scriptures, as well as to the early church fathers. For example, Philipp Melanchthon believed that God, in the days of the Reformation, “recalled the church to its origins.” See Lindberg, The European Reformations, 6.