I believe I've written before about the difficulty of having an original thought. (Diligent research confirms this.) The vast majority of our thoughts are the product of the prevailing thoughts of our culture. If our language lacks a word for something, it is nearly impossible for us to think about that thing. I had a philosophy professor at BYU who argued that thought could not occur without language. (This is my memory of what he said 20 years ago in a class I failed, so I could be wrong here.) Class members contended infants thought outside language, but the professor said once we learn a language, our thought happens within language.
I believe I've also written before about how a weeding-out process could raise the faith of the average group member by removing those of below-average faith. (Yep, some here and more extensively here.) But it's not just a matter of raising the average of 3, 4, 5, 6, and 7 by removing the 3; removing the 3 can allow the 4 to become a higher number.
It's really hard for me to have faith sufficient to be healed of my health problems when everyone around me is talking about how modern medicine that minimizes symptoms is how God heals people in modern times. The scriptures tell us of healings, not management of chronic conditions, and the scriptures are given to us to help us focus our faith. But they can't work when everyone around you is saying, "That's a metaphor."
I find a sliver of hope in the life of Abraham. When all his kinsmen in the land of the Chaldeans had turned to the worship of false gods, Abraham remained faithful. So it can be done, but it's awfully difficult to do.