In my 54 years of study, most of the changes that humans have made are inconsequential based on the actual texts. But the problem lies with how a man made doctrine is pulled out and twisted. When sticking strictly to the actual words of scripture based on context, culture and original meanings they remain the same excluding minor scribal errors or lack of understanding of what a Hebrew word really meant. This knowledge can only be achieved with focused study of each word. Man made doctrine started around 90 AD when they chose a new religion called christianity and moved it away from is root in the Israelite/Hebrew way of life. Back then people had no Bible, it was a rich mans possession. Everything was learned from "preachers" and their chosen interpretations to make their translations fit their doctrine. If you do the study the truth is there, Yehovehs Word is under His control and man cannot change it. It can only be twisted in men by satan in doctrine like he does with all creation