On 31 Oct 1517, Martin Luther (above) posted his “Ninety-Five Theses” on the door of the All Saints’ Church in Wittenberg Germany. These were ninety-five attacks on the perceived corruption of the Catholic Church.
Luther’s note caused a great controversy, and it triggered the Protestant Reformation, which involved two centuries of war and conflict.
Luther tacked it onto the church doors, because in those days churches were central meeting places for people at all socioeconomic levels.
There is an even more important document titled “The Twenty-Six Theses” that I wish had the same effect as did Luther’s note. I urge you to read it here.