Why was the creation of the printing press essential to the spread of the Reformation?

Since printing presses produced the same material regardless of where it was the messages and ideas that were in the theses were shared to everyone that read them regardless of location.

Explanation: This is a huge reason behind why the Protestant Reformation gained so much traction.

its main object was the establishment of "settlement houses" in poor urban areas, in which volunteer middle-class "settlement workers" would live, hoping to share knowledge and culture with, and alleviate the poverty of, their low-income neighbors.

the gutenberg bible was and about 180 copies were sold/made