“Y es preciso saber que un príncipe, y máxime un príncipe nuevo, no puede observar todo aquello por lo que los hombres son considerados buenos, dado que, para conservar el Estado, a menudo necesita obrar contra la lealtad, contra la caridad, contra la humanidad, contra la religión. Por eso necesita tener un ánimo dispuesto a moverse según se lo exijan los vientos de la fortuna y las variaciones de las cosas y, como he dicho antes, no alejarse del bien, si puede, pero saber entrar en el mal si es necesario. (...) Trate, pues, el príncipe de ganar y conservar el Estado y los medios siempre serán juzgados honorables y alabados por todos, porque el vulgo se deja conquistar por la apariencia y por el resultado final de las cosas, y en el mundo no hay más que vulgo''.”
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.