Why are "people of book" so easily decieved?

"People of book" are catholics-catechism,muslims-koran,commun… manifesto & other communist literature,feminists-teachings that say women require equality with men in all areas of life irrespective of the fact that weather they deserve it or not,teachings that promote gender role reversal,ual immorality and societial degeneration.These 4 groups can be called as "people of book" since they follow bluntly what is taught to them without any guidance of truth,reality and discernment(Jesus).