I don't understand why you find that incredible. Catholics have been telling me that for a long time.
The rest of the post is blah, blah, blah. Fact is the bible as defined by the Catholic Church was changed 1,000 years later. Whatever the reason this is a glaring issue that can't be ignored. Protestants have the true early church bible. Catholics have a bunch of addendums added to theirs.
People who are honest, sane, and not profoundly mentally deficient learn something when people tell them it over, over, and over again.