The Protestant Reformation began in 1517 when Martin Luther nailed his 95 Theses to the door of the church in Wittenberg, outlining abuses in the Catholic Church. Luther argued that salvation came through faith alone rather than good works and indulgences as taught by the Church. This split Western Christianity into Catholic and Protestant groups. Luther's writings spread through the printing press and he was eventually excommunicated. The Reformation led to religious freedom and divisions in Christianity that still exist today between Protestantism, Calvinism, and other groups like the Anabaptists.