Question

What role did the printing press have on the Protestant Reformation?

Answer 1

The simple answer is that it allowed Martin Luther's 95 theses to be printed faster than the Catholic church could burn them.
Think of it as the first "social media."
Once it was out there, you could not stop it.

Answer 2

Before the Protestant Reformation, man hand to hand write everything including the Holy Bible. The printing press was a more effective and quick way of making copies of the Bible and helped spread the Christian religion at a much faster pace.