Who posted his Ninety-five Theses on a church door in 1517?

Martin Luther.

In 1517, Martin Luther, a German monk and theologian, posted his Ninety-five Theses on the door of the Castle Church in Wittenberg, an event that would become a pivotal moment in religious and world history. This act is widely regarded as the catalyst for the Protestant Reformation, a movement that challenged the authority of the Roman Catholic Church and reshaped the religious, political, and cultural landscape of Europe.

Luther’s primary concern, as expressed in the Ninety-five Theses, was the sale of indulgences – payments made to the Church in exchange for the forgiveness of sins or a reduction in time spent in purgatory. Johann Tetzel, a Dominican friar, was one of the most prominent sellers of indulgences at the time, and his practices deeply troubled Luther. He viewed the indulgence system as corrupt and exploitative, arguing that salvation could not be bought but was instead a free gift from God, received through faith alone.

By posting his theses, Luther intended to initiate an academic debate about the practice of indulgences, but his ideas quickly spread beyond the confines of the university. The advent of the printing press allowed for the rapid dissemination of his writings, and within weeks, they were being discussed across Germany and other parts of Europe. Luther’s challenge to the Catholic Church led to significant theological debates, ultimately resulting in the splintering of Western Christianity into various Protestant denominations.

Luther’s bold act not only questioned Church practices but also emphasized individual conscience and the authority of Scripture over Church traditions. Consequently, his posting of the Ninety-five Theses on October 31, 1517, marks a defining moment in history, symbolizing the beginning of the Reformation era.