Did the invention of the printing press change Christianity? Before 1440 and the invention of the printing press, most Christians would not have had their own personal bible. So I would assume the only place they would see one would be in a church read by a Priest or other scholarly people.

Do you think this changed Christianity a lot from pre-15th century Christianity ?

Having your own Bible which you could refer to and read every day and debate people with must have been a lot different to the times when people had to go and consult the few copies.

I'm sure there were some richer people who could afford to have their own personal copies copied out by scribes.
Yes! Before the printing press the Roman Catholic Church did everything it could to limit the translation of the text into native languages and mass production of the text in Latin. The amount of power and control in doing so helped keep them as the #1 power on Earth for a millienia. Also the Protestant Reformation might not have occured without the printing press. Luther mass produced his 95 Thesis to spread around the churches faster than the church could remove them. It is my great hope that technology can once again allow the new awakening of knowledge through the internet.