Reformation

As you have learnt from the Renaissance, the pope was one of the wealthiest patrons to the artists.  Did you wonder... where did this money come from?  The money at the beginning came from the churches own wealth but as time went on the church needed money for the building of St. Peters and other artistic creations.  As a result tickets to heaven, known as Indulgences were sold to the christian followers of the pope.  A number of abuses now took place in the church...

Simony is the selling of sacred things.
Nepotism is the term used to describe giving jobs to unqualified relations.
Absenteeism is not turning up to mass etc.
Pluralism is holding more than one position in the church. 

The opposition to this corruption led people like Martin Luther and John Calvin to Protest against the church leading the church to SNAP and now new christian variants of the religion would form leaving : Catholicism, Lutheranism, Calvinism, Presbyterianism, Anglicanism, etc.

Counter Reformation

The Catholic church soon became concerned by the large number of followers which they were losing as a result of the Reformation.  The Council of Trent was called to discuss the abuses and to internally reform the church and bring back followers.  Only 28 bishops came to the council which created great concern.  The council decided to stop the sale of Indulgences, to end Simony, Nepotism, Absenteeism and Pluralism.  Seminaries were set up to educate priests.  Soon a new Society of Jesus known as the Jesuits were set up.  Inquisitions took place in places like Spain and Italy.  Those going against the teachings of the church would be questioned before the Courts of Inquisition.  Punishments ranged from having to wear a Sanbenitos (yellow cloak), to torture and being forced to recant, to being burnt at the stake at an Auto De Fe.