“Therefore, he who considers it necessary to secure himself in his new principality, to win friends, to overcome either by force or fraud, to make himself beloved and feared by the people, to be followed and revered by the soldiers, to exterminate those who have power or reason to hurt him, to change the old order of things for new, to be severe and gracious, magnanimous and liberal, to destroy a disloyal soldiery and to create new, to maintain friendship with kings and princes in such a way that they must help him with zeal and offend with caution, cannot find a more lively example than the actions of this man.”
Martin Luther changed the course of Western civilization by initiating the Protestant Reformation. As a priest and theology professor, he confronted indulgence salesmen with his 95 Theses in 1517. Luther strongly disputed their claim that freedom from God's punishment of sin could be purchased with money. His refusal to retract all of his writings at the demand of Pope Leo X in 1520 and the Holy Roman Emperor Charles V at the Diet of Worms meeting in 1521 resulted in his excommunication by the pope and condemnation as an outlaw by the emperor.
Luther taught that salvation is a free gift of God and received only by grace through faith in Jesus as redeemer from sin, not from good works. His theology challenged the authority of the pope of the Roman Catholic Church by teaching that the Bible is the only source of divinely revealed knowledge and opposed sacerdotalism by considering all baptized Christians to be a holy priesthood.
His translation of the Bible into the language of the people (instead of Latin) made it more accessible, causing a tremendous impact on the church and on German culture. It fostered the development of a standard version of the German language, added several principles to the art of translation, and influenced the translation into English of the King James Bible. His hymns inspired the development of singing in churches. His marriage to Katharina von Bora set a model for the practice of clerical marriage, allowing Protestant priests to marry.