In the early morning of October 31, 1517, one brave man nailed 95 arguments to a church door, and the world was never the same again—or so the story goes. The truth of the legend surrounding Martin Luther’s 95 Theses notwithstanding, it is hard to dispute the world changing effect that this German monk would have. Luther is often given credit for beginning the Protestant Reformation with his 95 Theses in 1517, and a commonly cited ending is the Treaty of Westphalia in 1648, although theological disputes, dialogues, and divisions continue to the present day.
Luther lived in an age where there were many deep problems in the Church: the Western Schism eroded faith in the papacy, simony and corruption were rampant, and philosophies of nominalism and humanism were pushing scholastic thought out of the universities. Everyone recognized that the problems desperately needed solutions, and in some places progress was made, such as Spain. Different attempts at general reform were attempted, but nothing had so wide an effect as Luther’s work.
The issue that started Luther down the road to breaking from Rome was indulgences. An indulgence is “a remission before God of the temporal punishment due to sins whose guilt has already been forgiven.” They can be obtained in a variety of ways, and in Luther’s time, they were being sold in order to fund the construction of St. Peter’s Basilica. Luther’s 95 Theses were written to his bishop in order to raise some questions he had about the way the sale of indulgences was being conducted in his area. At this point Luther had no intention of breaking with the Church or challenging the authority of his superiors, he was just asking questions. However, his bishop did not start a discussion on the question raised as Luther wanted. Luther was question by a Papal representative, and the meeting degenerated into a shouting match.
Around this time his work began to take on a more radical tone. Before, he had been raising questions about certain church practices, but increasing he separated himself from Church doctrine. His key claims were that man is justified by faith alone (sola fide) and that Scripture is the only source of doctrine (sola scriptura). Luther was summoned to account for these teachings at the Diet of Worms. After a lengthy debate presided over by Emperor Charles V, Luther was condemned as a heretic and outlaw. He allegedly declared, “Here I stand. I can do no other.” But none of this happened in a vacuum, and certain princes saw that they could use Luther as a weapon against the power of the emperor and the church. And things exploded.
The story of Luther was only the beginning. Shortly thereafter, other reformers started to publish their ideas, often disagreeing with Luther. These numerous reformers went on to found the other strains of Protestantism. John Calvin originated the Reformed tradition which includes Presbyterianism and Congregationalism. More groups would sprout off from the Church of England which King Henry VIII founded by breaking with the Roman Church. Relations between the different groups of Protestants were often as bad as those between Protestants and Catholics.
Once political leaders started to take sides in the religious conflict, war broke out almost immediately. The Thirty Years War—the collection of wars broadly encompassing Catholics and Protestants—amassed over 8 million casualties was one of the most destructive European conflicts until the Napoleonic Era. It ended with the Treaty of Westphalia which many credit with creating the modern idea of national sovereignty.
In response to the Reformation, the Catholic Church began what is called the Counter-Reformation, or Catholic Reformation. It was started by the Council of Trent (1545-63) which defended traditional church teachings, weeded out corruption, created better training for clergy, and saw the spread of new spiritual movements and religious orders (including the Jesuits).
Although Protestants and Catholics still disagree on much, there has been progress made on some fronts. In 1999, Catholic and Lutheran theologians crafted a document “Joint Declaration of Doctrine of Justification” in which they came to an agreement on the good works vs. faith alone argument. Just this past July, the World Council of Reformed Churches signed onto the document also. While we remain divided, some of the most controversial arguments are being resolved.