In two years from now, many Christians will be commemorating the 500th anniversary of the Protestant Reformation. Already there are signs of this significant date approaching. The German toy company PLAYMOBIL has even issued a special, commemorative, limited edition figure of Martin Luther; and it’s already sold out!
While many of my colleagues at Reformed Theological Seminary are already thinking about 2017, most of us are not aware of a very important church history anniversary this fall. I’m thinking, of course, of the 500th anniversary of Luther’s lectures on the Book of Romans, which helped pave the way for the Reformation of 1517.
Let me remind you of the significance of the book of Romans. I am often surprised at how many Christians avoid or are afraid of this powerful letter from Paul to the early church in Rome.
Church history testifies, over and over, to the power of this little letter. Romans is simply a life-changing gospel manifesto—a truly revolutionary book.
Recall that in the early church, Augustine came to faith in Christ after hearing a voice say “take up and read.” What did he take up? It was part of the book of Romans,
Martin Luther himself was transformed by reading this book. He said Romans “is really the chief part of the New Testament and the purest gospel. It is worthy not only that every Christian should know it word for word, by heart, but also that he should occupy himself with it every day, as the daily bread of the soul. The more we deal with it, the more precious it becomes and the better it tastes.” 
Sometime later, John Calvin was also profoundly moved by his encounter with Romans. Calvin wrote, “When we have gained a true understanding of this Epistle, we have a door opened to us to all the most profound treasures of Scripture.” 
John Wesley attributes his conversion to a day in London when he stepped into an Moravian chapel on Aldersgate Street in London and heard someone reading from the preface to Luther’s Commentary—on Romans.
Or think of Swiss theologian Karl Barth. After a failed pastorate, he rediscovered what he called “the goodness of God” through his study of the book—of Romans. He too wrote a book about this, that people described as a bombshell that hit the liberal theological world of Europe not long after World War I.
Why is this book of Romans so powerful? New Testament scholar F.F. Bruce answers the question when he describes Romans as “a sustained and coherent statement of the gospel.”  Or as I sometimes say, the gospel is as simple as John 3.16, yet it is as deep and profound as the book of Romans.
Two years before 1517, Luther was lecturing on Romans at the university of Wittenburg. His study challenged him to think differently about God’s righteousness, especially as he studied Romans 1.16,17. That passage reads: For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. For in it the righteousness of God is revealed from faith for faith, as it is written, “The righteous shall live by faith.”
Previous to his study of Romans 1, when Luther read about the righteousness of God, he thought of righteousness simply as a divine attribute, i.e., that God is extremely righteous. Before this righteous God, Luther felt condemned in his sin.
Luther did not try to explain away God’s righteousness (or his own real guilt) the way moderns try to. Instead, he discovered that the righteousness referred to here is not only the righteousness by which God himself is righteous, but also a righteousness that God grants to us as a gift by faith, so that we can meet the demands of his justice and be pardoned of our sins.
These verses, and Romans, speak of a righteousness from heaven which God imputes to sinners by faith. The righteous Christ came to die for unrighteous people like us to bring us back to God. Christ died on a cross, absorbing the divine judgment we deserve, so that we might escape.
On the cross, God transferred our sins onto Christ, and now offers Christ’s right standing to us as a gift—so that we might be reconciled to God and declared righteous in his sight. Put another way, God justifies sinners who come to him by grace alone, through faith alone, in Christ alone. This is why Romans says the righteous shall live by faith.
Without this rediscovery of the gospel, would the Reformation have happened? I don’t think so. Because in order to happen, it needed a super powerful message. And the most powerful message in the world is the gospel itself.
Luther personally discovered the powerful gospel of the powerful Christ. And that discovery began, not in 1517, but in 1515, with the book of Romans.
From his introduction to the Commentary on the Epistle to the Romans, Martin Luther (1522). The Works of Martin Luther, Volume VI, (pp. 447-462). Muhlenberg Press, Philadelphia.
 From Calvin’s first commentary on the book of Romans.
 A Mind for What Matters, Collected Essays of F.F. Bruce, F. F. Bruce., Wm. B. Eerdmans, Publishing Co., Grand Rapids, 1990, p. 85