Martin Luther was a law student who lived in Germany. Near Stotterheim when returning back to the university of Erfurt on July the 2nd 1505, lightning struck near him and said "help me St.Anne if I live I will become a monk.
Since Martin Luther survived the lightning bolt he became a monk. During a diplomatic mission in Rome, he saw priest rushing through church and taking light of there duties. So when traveling through Rome he wrote about the corruption and sin of the city and the church.
When Martin Luther went to the city of Wittenberg, he saw the church selling indulgences. Indulgences where a piece of paper that allowed a person to have lessen time in purgatory. Martin Luther believed that sin could not be fixed through actions or words, but only faith. This was called Sola Fide. on the 31st of October he nailed a 95 theses to the church of Wittenberg.
Want to go against the peasants and the church?
Due to the theses the church called him a hieratic and he was held before the council of trent prove his ideas against the church. The church decided to excommunicate him from the church and send him to Germany. In Germany he used the printing press that was invented in 1440 to rewrite the bible from Italian to German so people could read it in hopes that it will allow the people to see the sins of the church.
Due to Martin Luther rewriting the bible in german, so the people could read it worked as more and more citizens rebelled against the church. But instead of everyone unifying against the church, more religions were made such as the Calvins and Anna Baptist. This resulted in a massive peasant army of 300,000 not only against the church but the monarchs as well.
Martin Luther disliked how his idea backfired against him and sided with the monarchs to fight the church and the peasant army. The monarchs joined Luther because they could gain money, power and land if they took church land and the peasant army was slaughtered.