From Claude.ai on 7/26/2026. Also see Bart’s post here.
Background: Indulgences and Church Corruption
By the early sixteenth century, the sale of indulgences—documents claiming to reduce or eliminate the temporal punishment for sin—had become a significant source of controversy in the Catholic Church. The Catholic Church’s practice of granting indulgences to provide absolution to sinners became increasingly corrupt, and although indulgence-selling had technically been banned in parts of Germany, the practice continued unabated. In 1517, a Dominican friar named Johann Tetzel, commissioned by the Archbishop of Mainz and Pope Leo X, was conducting a major fundraising campaign in Germany to finance the renovation of St. Peter’s Basilica in Rome. Although Prince Frederick III the Wise had banned the sale of indulgences in Wittenberg itself, many local church members traveled elsewhere to purchase them, then returned home showing off their pardons and claiming they no longer needed to repent. HISTORY + 2
Luther’s Position and the Posting of the Theses
Martin Luther, an Augustinian monk who had been appointed professor of biblical theology at the University of Wittenberg, was outraged by this practice. Sometime during October 31, 1517—the day before the Feast of All Saints—the 33-year-old Luther posted his theses on the door of the Castle Church in Wittenberg, which functioned as a bulletin board for academic and church announcements. The theses were written in Latin and printed on a folio sheet by the printer John Gruenenberg. Luther’s stated purpose was academic: he was calling for a “disputation on the power and efficacy of indulgences out of love and zeal for truth and the desire to bring it to light.” Christian History Institute + 3
It’s worth noting that the popular image of Luther defiantly hammering the document to the door is likely more legend than fact. The reality was probably not so dramatic—Luther more likely hung the document on the door in a matter-of-fact way to announce an upcoming academic discussion. Historians have examined the best evidence for and against this famous story, though in either case it is correct to say Luther posted the 95 Theses on October 31, 1517, since that is the date on the cover letter he mailed to local German bishops. HISTORYjhu
Content and Theological Core
The first two theses contained Luther’s central idea—that God intended believers to seek repentance, and that faith alone, not deeds, would lead to salvation—with the remaining 93 theses, many directly criticizing indulgences, supporting these first two. This conviction was rooted in Luther’s reading of Paul, particularly the idea that “the one who is righteous will live by faith” (Romans 1:17, NRSV). Though originally intended to promote academic discussion, the theses became a manifesto that turned a protest about a German indulgence scandal into what has been called the greatest crisis in the history of Western Christianity. HISTORYEncyclopedia Britannica
Rapid Spread and Consequences
The theses did not stay confined to academic circles. They were quickly snapped up, translated from Latin into German, and distributed widely; a copy made its way to Rome, prompting efforts to convince Luther to change course. Albert of Brandenburg, the archbishop of Mainz, sent the theses to theologians whose judgment moved him to forward a copy to Rome and demand action against Luther; by early 1518 the theses had been reprinted in many cities, and Luther’s name had become associated with demands for radical reform. The recent invention of the printing press allowed the message to spread rapidly across Europe, reaching both clergy and common people. HISTORY + 2
Luther refused to recant. He was formally excommunicated by Pope Leo X in 1521, and that same year he again refused to recant before the Holy Roman Emperor Charles V, who issued the Edict of Worms declaring Luther an outlaw and heretic. HISTORY
Luther’s Bible Translation
Exile at the Wartburg
Following the Diet of Worms, Prince Frederick protected Luther, and Luther began working on a German translation of the Bible, a task that took roughly 10 years to complete in full. Luther was sheltered at Wartburg Castle for about ten months beginning May 4, 1521, hidden under the alias “Junker Jörg.” In his study high above Eisenach, he translated the New Testament into German within a few weeks during the winter of 1521–1522. More precisely, he began with the New Testament in November or December 1521 and completed it the following March, before leaving the Wartburg. HISTORY + 3
Translation Method and Sources
Luther did not translate from the Latin Vulgate used by the Catholic Church, but from the original languages. He and his colleagues based their translation on original manuscripts, using works such as Erasmus’s critical Greek edition of the New Testament rather than the Vulgate. Specifically, his translation was based on the second edition of the Greek text edited by Erasmus in 1519. He was also assisted significantly by colleagues: Melanchthon was astounded by the quality of the translation and persuaded Luther to do a more systematic job. Lutheran Reformation + 2
Publication of the New Testament (1522)
Luther’s illness, the Peasants’ War, and the demands of ecclesiastical and political developments prevented him from working on the Old Testament with the same peaceful concentration he had enjoyed at the Wartburg. Before that, though, the New Testament was finished and revised. The spring of 1522 was dedicated to revisions and corrections, and the New Testament was ready for the press by late September. In September 1522, Luther published the first edition of his New Testament translation, known as the “September Testament”; some 3,000–5,000 copies were printed, and by December a second edition (the “December Testament”) had to be published. The price was one guilder—roughly two months’ salary for a schoolmaster. The book’s debut at the Frankfurt Book Fair in September 1522 sparked a cultural and theological upheaval, since it was the first time ordinary German people had access to a New Testament in their own language. Christian Library + 4
Translating the Old Testament (1523–1534)
Luther then turned to the more demanding work of the Old Testament. He proceeded to translate it in parts as they were completed—the Pentateuch appeared in 1523, and the Psalter in 1524. In the course of this work he founded a “Collegium Biblicum,” or Bible club, made up of colleagues including Melanchthon, Bugenhagen, Cruciger, Justus Jonas, and Aurogallus. A team of his Wittenberg colleagues—among them Matthew Aurogallus, Justus Jonas, Caspar Cruciger, and Melanchthon—assisted Luther in translating the Old Testament between 1523 and 1534. To aid him, Luther also enlisted the Hebrew scholar Matthew Aurogallus, and the work of the Hebraist Reuchlin proved valuable as they struggled with difficult passages in Job and the prophets. Bible Researcher + 3
The Complete Bible (1534)
The translation of the entire Bible into German was published in a six-part edition in 1534, a collaborative effort of Luther, Johannes Bugenhagen, Justus Jonas, Caspar Creuziger, Philipp Melanchthon, Matthäus Aurogallus, and Georg Rörer. The completed Bible contained 75 books, including the Old Testament, Apocrypha, and New Testament. Notably, Luther continued refining the translation up until his death in 1546, having worked on the edition that was printed that same year. Textus Receptus + 2
Impact and Legacy
The scale of the New Testament’s circulation alone was remarkable: by the time Luther published the complete Bible in 1534, 87 editions of his New Testament had appeared in High German and some 19 in Low German, with more than 200,000 copies sold. The nineteenth-century historian Philip Schaff called it “the richest fruit of Luther’s leisure in the Wartburg, and the most important and useful work of his whole life,” through which he “brought the teaching and example of Christ and the Apostles to the mind and heart of the Germans in life-like reproduction,” making “the Bible the people’s book in church, school, and house.” LstcTextus Receptus
Beyond Germany, Luther’s Bible influenced English translations through William Tyndale, helped form the modern German language, prompted educational reforms that advanced literacy, and its language was later carried into the works of composers like J.S. Bach and Johannes Brahms. More broadly, translation of the Bible into vernacular languages became standard missionary practice, often preserving languages that might otherwise have been lost—but perhaps most significantly, Luther’s Bible helped carry the ideas of the Reformation directly to ordinary laypeople. 15171517
Sources: World History Encyclopedia; HISTORY.com (two articles); Christian History Institute; Encyclopaedia Britannica; Timeline of the Reformation (JHU Press); die-bibel.de; Musée protestant; The Gruber Collection (Lutheran School of Theology at Chicago); Christian Study Library; Word & World (Luther Seminary); 1517.org; Bible Researcher; Lutheran Reformation; Wikipedia (Luther Bible).
