“A prince is also respected when he is either a true friend or a downright enemy, that to say, when, without any reservation, he declares himself in favour of one party against the other; which course will always be more advantageous than standing neutral; because if two of your powerful neighbours come to blows, they are of such a character that, if one of them conquers, you have either to fear him or not. In either case it will always be more advantageous for you to declare yourself and to make war strenuously; because, in the first case, if you do not declare yourself, you will invariably fall a prey to the conqueror, to the pleasure and satisfaction of him who has been conquered, and you will have no reasons to offer, nor anything to protect or to shelter you. Because he who conquers does not want doubtful friends who will not aid him in the time of trial; and he who loses will not harbour you because you did not willingly, sword in hand, court his fate.”
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.