In September 1522, one of the most important events of the Reformation occurred: Martin Luther’s translation of the New Testament was published. It came to be known as the “September Testament,” and looking back 500 years later, we can see that it not only shaped the reformers’ theology but also was as big an influence on the German language as Shakespeare was for English.

Following his appearance at the Diet of Worms and the subsequent imperial edict that banned his writings and the reformer himself, Luther went into hiding at the Wartburg Castle in the spring of 1521. This development shifted Luther’s life of frenetic activity and constant defensive maneuvers to a solitary life with neither monastic schedule nor regular conversations with friends and colleagues. Luther needed at least a resemblance of activity and immediately kept up regular correspondence with people back home in Wittenberg.

Luther complained to his friends about not being busy. To Georg Spalatin, he wrote, “I am sitting here all day, drunk with leisure.” But thanks to the reduced external demands, Luther’s months in exile at the Wartburg were extremely productive. While he experienced worse bouts of constipation than he’d had at home, we could say he indeed let it flow from the nib of his quill. Within three weeks of his arrival at the castle, he had already completed the manuscript of a book.

Before he was snatched away by “bandits” (in reality, some of his prince’s henchmen) who transferred him safely to the Wartburg, Luther successfully grabbed his satchel of books, including the Old and New Testaments in Hebrew and Greek. He didn’t have any philological help, but he told Spalatin he was regularly reading Scripture in the original languages. Midway through his stay, Luther did a surreptitious visit to Wittenberg and asked that he be sent a copy of Erasmus of Rotterdam’s newly published and more accurate Greek New Testament. With that in hand, Luther spent his last eleven weeks at the Wartburg translating the text to German.

Around two months after Luther’s return to Wittenberg on March 6, the initial pages of the translation came off the three presses that printer Melchior Lotter had dedicated to the hefty job. Those two months allowed the court artist Lucas Cranach to create initial illustrations for each of the twenty-seven books. (Luther at first was also unsure of whether all should be included on account of questions about the clarity of James or Revelation.) Of much greater importance was getting the languages right — both understanding the meaning of the Greek text and of landing on the best words and phrases to open the text in the vernacular for German readers. While the initial Wartburg translation was Luther’s, the final result came through the efforts of a wider Wittenberg circle.

The resulting “September Testament” was published in time for the Frankfurt Fair, the biannual publishing marketplace offering greater reach than Leipzig’s regional fair. It’s an understatement to say it was a bestseller. In response, Jerome Emser, the secretary to Duke George of Saxony, one of Luther’s most vituperative antagonists, produced his own New Testament translation, in part as a way to counter the unprecedented sales figures of Luther’s work.

Luther’s goal in translating was to move from the letter to the spirit. He wanted readers of Scripture to encounter more than mere ink blots on paper.

It was an age without copyright laws, so other publishers soon issued their own copies of Lotter’s edition. Emser’s translation not only aimed to grab the cash cow but also sought to pull attention away from the Wittenberg reformer. Although he claimed it fixed Luther’s errors and served as a “new” edition, it can be categorized as blatant plagiarism. It even included versions of Cranach’s full-page woodcuts.

The testament Frankfurt fair-goers purchased included not only Cranach’s detailed illustrations but also prefaces Luther wrote for each book in the New Testament. These were intended as guides that would provide readers with a theological lens for entering the text. As Luther later wrote in his debate with Erasmus over free will, Scripture is perfectly clear…if you know what to look for. The prefaces taught the language and grammar of the gospel so that readers’ understanding could be guided. In other words, Luther was a spin doctor, but in the least pejorative sense. As he later said, in the translation he taught “my ungrateful pupils, even my enemies, how to speak.”

The September Testament was not the first Bible translated into German (the full Bible would come several years and much greater labor later), but it did more than provide a literal word-for-word equivalence of previous editions. Those had Jerome’s Latin Vulgate translation as their source rather than the Greek text and passed down errors that came from misunderstanding the ancient language or from Jerome not having the best original fragments and manuscripts available to him.

Luther’s goal in translating was to move from the letter to the spirit. He wanted readers of Scripture to encounter more than mere ink blots on paper. For him, God’s word was a living word, but it wouldn’t come alive or have the power to create saving faith if it was in an incomprehensible language or if a translation didn’t accurately reflect the original text. In a way, Luther acted out Jesus’ words at the end of his string of “lost” parables in Matthew 13:52: “Therefore every scribe who has become a disciple in the kingdom of heaven is like the master of a household who brings out of his treasure what is new and what is old.” The German word for “vocabulary” is “Wortschatz,” literally “word treasure.” The process of translating is one of dealing with both the old language and its new counterpart.

Luther was a master translator and not very humble about his acumen.

When Luther was holed up in another castle, the Coburg, during the Diet of Augsburg in 1530, he wrote: “On Translating: An Open Letter,” in which he explained how he aimed to bring out the gospel treasure in the text of the New Testament. The catalyst for the letter was the complaints his theological opponents, beginning with Emser, had continually made about his translation in the eight years since it had been published. The primary gripe was that Luther had added words in German that weren’t present in Greek.

Luther was a master translator and not very humble about his acumen. In the “Open Letter,” he said, “If I were to have asked them how to put into German the first two words of Matthew’s Gospel, Liber Generationis, none of them would have been able to say Quack! And now they sit in judgment on my whole work!” Luther asserted that translation required the translator to understand that a word-for-word rendition in the new language was unacceptable, and he marshaled a litany of instances where the literal option would be gobbledegook for German ears.

The passage that Luther’s opponents most abhorred (and that many still object to today) was his rendering of Romans 3:28, in which he included the word “alone” in Paul’s statement on justification by faith. He said they look at the four letters, S O L A, like cows staring at a new gate, as if they had never encountered the idea of faith alone before. But, he argued, “it belongs there if the translation is to be clear and vigorous. I wanted to speak German, not Latin or Greek.” While Latin and Greek implied justification was by faith alone, the structure of the German language required that it be made explicit.

In the “Open Letter,” Luther revealed his underlying goal in the September Testament and subsequent translations. “We do not have to inquire of the literal Latin, how we are to speak German… [W]e must inquire about this of the mother in the home, the children on the street, the common man in the marketplace. We must be guided by their language, the way they speak, and do our translating accordingly. That way they will understand it and recognize that we are speaking German to them.”

The hundreds of printed pages from Lotter’s presses and countless others were such an accurate reflection of the German of the day that they cemented the language’s spelling and usage for the following centuries. What’s more, if the September Testament spoke the German of Luther’s people, it would be much more certain that Scripture would be a “for you” living word from God. For five hundred years, believers have experienced it as just that.