Martin Luther (1483-1546) was the forerunner of the Reformation. He was a German scholar and theologian who reacted against the corruption of the Catholic Church and its practice of selling indulgences (eternal salvation was sold to raise money). On October 31, 1517, he nailed his Ninety-five Theses attacking papal abuses and the sale of indulgences to a church door in Wittenberg. The pope was very irritated and excommunicated Luther (cut him off from the Church). However, many people agreed with his criticisms and joined his protest against the Catholic Church. They became known as PROTESTANTS. The Protestant movement spread from Germany to Scandinavia and Scotland.
Henry VIII was the king of England (1509-1547). Henry was a devout Catholic, thus he reacted against Luther’s Theses, and wrote a treatise A Defense of the Seven Sacraments (1521), defending the Catholic point of view. The pope rewarded him with a new title Defender of the Faith. However, he was eager to divorce Catherine of Aragon because he wanted to marry Anne Boleyn, in the hope of Anne giving him a male heir to the throne. He asked the Pope to annul his first marriage, but the Pope delayed an answer. Eventually, Henry VIII passed the Act of Supremacy (1535) declaring himself as the Supreme Head of the Church, breaking the ties with Rome. The authority of the Pope was no longer recognized in England. This marked the beginning of the Reformation in England.
John Calvin (1509-1564) was a prominent French theologian. Due to violence in France, he had to flee to Geneva, Switzerland. There he became the leader of the Swiss Protestant Reformation. One of the central tenets of Calvinist theology is predestination (belief that God determines beforehand who will be saved). Calvinist ideas deeply affected Protestantism in Europe, and even spread to other parts of the world including North America, South Africa, and Korea.