Why did the invention of the printing press had a great effect on society?

The printing press increased the spread of information much like the internet does today.

Information has a great impact on what people believe. What people believe affects how people behave and the cultural norms they follow.

The printing press made information more easily available to the"common" people. Information that was controlled, restricted, or limited to the wealthy became accessible to the general population.

A prime example is the printing of the Bible. The Luther's Reformation resulting in the Protestant church was successful largely because of the printing press.

Earlier Biblical translations and attempts at the reformation of the Catholic Church failed. The Catholic Church was able to use political force to outlaw ( ban) the use of the Biblical translations. Because all copies of the translations had to be hand written, it was possible for the Catholic church to find and burn most of the copies of these early translations.

Peter Waldo made a translation from the ancient Latin into the local French. (1173) The Waldenses declared a heretic group by the Catholic church had existed in the high valleys of the alps for hundreds of years. Peter Waldo who was a part of the Waldenses became a missionary to southern France.

The people of Southern France became followers of Peter Waldo's translation, more than the Catholic Church. A Crusade was declared against the Waldenses as well as other non conforming Christian groups by Pope Innocent III. The Waldenses were killed, and their Bibles burned and the reformation was extinguished

John Wycliff made a translation of the Bible into English for the common people. His followers known as Lollards followed the Bible more than the Catholic Church. The official Catholic church banned the translations and burned every copy that was found. The Lollards were declared heretics and had to recant or be killed. This reformation also was extinguished.

Jon Huss of Bohemia (Czech) made a translation of the Bible into the local language. Jon Huss was burned at the stake as well as any copies of his Bible that could be found. His followers called Hussites fought several wars against the Catholic forces before being overcome.

All of these previous attempts at reformation were made before the printing press which made restricting the information possible.

Luther's reformation was made after the printing press and it was impossible to destroy all copies of Luther's translation of the German Bible and his other writings. Without the printing press reformation probably would have also failed.