Martin Luther wrote "The Ninety-Five Theses" because he was dissatisfied with several practices of the Roman Catholic Church, including the sale of indulgences, the abuse of priestly power and the power of the Pope. He also argued that faith, not deeds, is the path to salvation. By making these arguments public, he sparked a religious revolution that came to be known as the Protestant Reformation.
Even as a student, Martin Luther began to have some trouble with the Roman Catholic Church's teachings that one could reach salvation by performing certain acts. However, it was not until the Church began selling indulgences that his theological concerns coincided with concerns about priestly corruption. Indulgences allowed a person who gave money to the Church to avoid some of the temporal punishment associated with his or her sins. One could also buy indulgences to limit the temporal punishment of someone else, whether they were alive or in purgatory. When Pope Leo X announced a new round of indulgences in 1517 to finance the building of St. Peter's Basilica, Luther became enraged. He wrote "The Ninety-Five These," arguing that a person did not have to pay for remission of his or her sins because such forgiveness is offered by Christ freely to every person who repents. Nailing them to the door of the university chapel in Wittenberg, Germany, Luther started a discussion about the power of the Catholic Church that led to a huge number of new Protestant denominations.