Martin Luther (1483 β 1546) I started reading about him because of his hymns and advocacy for music. J.S. Bach and other composers of the north German organ school, whose compositions I've studied, used Luther's and Lutheran hymns in their works.
I've read his catechisms, and I find his ideas are still very appropriate and applicable in today's world. He argued that the head of the household should discipline the family in Scripture. The three parts of Christendom which Luther said should be memorized and constantly repeated are the Ten Commandments, the Creed, and the Lord's Prayer. St. Augustine had a large influence on Luther and is referenced throughout his major works.
In the Smalcald Articles (1537) Luther said of the papacy: "The pope is not, according to divine law or God's Word, the head of all Christendom. This name belongs to One only, whose name is Jesus Christ." And so as seen here Luther was in stark opposition to the pope and the government of the Roman Catholic Church. He also held contention with the mass in the papacy, the invocation of saints, and monastic vows.