How did cultural movements like the Renaissance and the Scientific Revolution destabilize the Catholic Church and pave the way for the reformation?

Answer 1

This are two very different subjects. The Scientific Revolution, if you will, did not contribute to the "destabilization" of the Catholic Church, and was, in fact, a direct result of the contributions of many priests and religious. It would not be out of line to say that there would have been no scientific revolution without the Catholic Church, and this has continued down to the present day.

The cultural movement referred to as the Renaissance was a return to the classics of the pre-Christian era. Again, this was championed by many in the Church, the greatest philosopher/theologian of all time, St. Thomas Aquinas, took the newly discovered works of Aristotle as his basis and developed an entire system of Christian thought that has never been surpassed, and is still used to teach philosophy and theology in the seminary to this day.

In the later Renaissance, however, a movement away from the rationalism rooted in the reality of the created universe and the reality of everything being contingent upon God gave way to a Humanism that saw the human being and his works as the pinnacle of the world. This view denied all the higher realities which had governed the world for centuries, and greatly impoverished it. This particular branch of the later Renaissance led to a cold, analytic, business mind that was divorced from the church and tried to compartmentalize religion apart from the daily lives of the people. This is what led to the protestant revolt.

All of this did not really destabilize the Catholic Church so much as just remove whole states of people from being able to receive the sacraments that they needed to achieve salvation as the Peace of Westphalia said that all the people of a particular state had to follow the religion of the ruler. The Church, itself, came out of this time of upheaval purified and much stronger producing many great saints and religious Orders, but many people were denied access to her.