just ask a protestant who wrote and kept the bible for the first 1200 years or so......
I call them DENIERS.
Without the Authority and Infallibility of the Catholic church given by the Holy Spirit there would be no Bible. If the Catholic church was fallible the the Bible is not worth the paper it is printed on.
Because the Protestant do not have this Authority they can take books(Luther) or add books(LDS) to Holy Scripture
(Note not everything the Catholic Church does is infallible it is only on Faith and Morals that the authority to declare infallible exists)