Committed to the idea that salvation could be reached through faith and by divine grace only, Luther vigorously objected to the corrupt practice of selling indulgences. Acting on this belief, he wrote the “Disputation on the Power and Efficacy of Indulgences,” also known as “The 95 Theses,” a list of questions and propositions for debate. Popular legend has it that on October 31, 1517 Luther defiantly nailed a copy of his 95 Theses to the door of the Wittenberg Castle church. The reality was probably not so dramatic; Luther more likely hung the document on the door of the church matter-of-factly to announce the ensuing academic discussion around it that he was organizing.
The 95 Theses, which would later become the foundation of the Protestant Reformation, were written in a remarkably humble and academic tone, questioning rather than accusing.
The overall thrust of the document was nonetheless quite provocative. The first two of the theses contained Luther’s central idea, that God intended believers to seek repentance and that faith alone, and not deeds, would lead to salvation. The other 93 theses, a number of them directly criticizing the practice of indulgences, supported these first two.
The 95 Theses were quickly distributed throughout Germany and then made their way to Rome. In 1518, Luther was summoned to Augsburg, a city in southern Germany, to defend his opinions before an imperial diet (assembly). A debate lasting three days between Luther and Cardinal Thomas Cajetan produced no agreement. Cajetan defended the church’s use of indulgences, but Luther refused to recant and returned to Wittenberg.