Background
The Protestant Reformation was a major turning point in history. Not only did it affect religious life in Europe, but also affected social, political, and economic institutions as well.  The Reformation's leaders were Martin Luther and John Calvin, both educated as priests for the Catholic Church.  The Reformation was a protest against perceived wrong doings by the Catholic Church.  The followers of Luther and Calvin became known as Protestants, because of their "protesting."

Causes
Church Corruption: By the 1500s the Catholic Church was the most wealthy and powerful institution in Europe.  Many church leaders lived more like kings, than priests, and became increasingly involved in political matters. To raise money for these activities, the Church raised fees for services such as, marriage and baptism, and also began the sale of indulgences, which were letters of forgiveness for one's sins.  This caused both anger and resentment across Europe, and many called for reforms to take place.

Martin Luther
Martin Luther was a German monk who was concerned about the sale of indulgences and other corruptions in the church.  In 1517, he wrote his 95 Theses, which were 95 arguments against the sale of indulgences. He posted these on the door of the Wittenberg church in protest. The Catholic Church ordered Luther to recant, or take back his theses, but he refused.  The Church excommunicated him, and would have executed him had they been able to capture him.  Luther's ideas spread quickly throughout the Germany and Scandinavia, mainly due to the new printing press.  Luther's beliefs are what sparked the Reformation.

Beliefs
Luther believed that Christians could only reach salvation through faith in god.  He did not believe that the Pope or other priests had any special powers, including the forgiveness of sins.  Luther's beliefs became the basis for the Protestant form of Christianity.

John Calvin
John Calvin was another priest - turned reformer.  Like Luther, he believed that faith in god provided the path to salvation, but he also promoted the idea of predestination.  Predestination is the belief that certain people were chosen by god for salvation. Followers of Calvin all believed they were predestined for heaven.  They setup religious communities throughout Europe and lived very strict, moral lives.

Counter/Catholic Reformation
As a response to the Protestant Reformation, the Catholic Church began a program to enact reform from within.  The purpose of the Counter/Catholic Reformation was to end corruption, return to traditional teachings, and to strengthen the church in an attempt to stop its members from converting.  Pope Paul III called the Council of Trent in 1545 to institution these reforms.  The Council setup new schools for priests, ended most corruption, and created new religious orders to deal with these problems.

The Society of Jesus
The Society of Jesus was founded by Ignatius Loyola to combat the Protestant Reformation by providing strong Catholic leadership to monarchs across Europe.  Jesuit training emphasized spiritual and moral discipline, as well as strict loyalty to the Church.  Jesuits did much to slow the spread of the Protestant Reformation, and later became very successful as missionaries, spreading the Catholic faith throughout the rest of the world.

Effects
Luther's and Calvin's ideas spread across Europe quickly.  This was due to unrest in the peasant population, inventions like the printing press, and the support of rulers wishing to free themselves from Catholic control. Religious unity in Europe was lost, which resulted in many wars including, civil wars in Germany and France, and wars between Protestant England and Catholic France and Spain.

The Reformation also leads to a period of anti-Semitism.  Both Catholics and Protestants place restrictions on Jews, often forcing them to live in separate areas of town.  Witch hunts also increased as many people, caught up in religious zeal, accuse others of Satanism.  Thousands were killed as a result, most of them women.

Overall, the Protestant Reformation and the Counter/Catholic Reformation changed the face of society in Europe.  Before the Reformation, Europe was united behind a single faith, with a strong Church for guidance.  By the end, Europe is divided religiously, and strong monarchs fill the leadership void left as a result of a weakened Catholic Church.