He refused to keep silent, however, and in 1521 Pope Leo X formally excommunicated Luther from the Catholic Church.
That same year, Luther again refused to recant his writings before the Holy Roman Emperor Charles V of Germany, who issued the famous Edict of Worms declaring Luther an outlaw and a heretic and giving permission for anyone to kill him without consequence.
By the time Luther died, of natural causes, in 1546, his revolutionary beliefs had formed the basis for the Protestant Reformation, which would over the next three centuries revolutionise Western civilisation and Western thought.
In 1517, Luther posts his 95 theses on the church door at Wittenberg.
At the time, a Dominican priest named Johann Tetzel, commissioned by the Archbishop of Mainz and Pope Leo X, was in the midst of a major fundraising campaign in Germany to finance the renovation of St. Though Prince Frederick III the Wise had banned the sale of indulgences in Wittenberg, many church members travelled to purchase them.
When they returned, they showed the pardons they had bought to Luther, claiming they no longer had to repent for their sins.
Martin Luther never criticized the papacy, however, and never called it out.
He said that he understood the purpose of the sales, but disagreed with them, and thus was looking for reform within the church.
Martin Luther's "Ninety-Five Theses" is a list of grievances regarding the sale of indulgences to the faithful.
Luther offers Biblical support for his argument, in which he states that the sale of indulgences in exchange for a)penance for present and future sins or b)penance for the dead's sins is a practice which goes against the foundations of the church's doctrine on eternal salvation or damnation.