The sad fact of the matter is that the vast majority of the people who consider themselves Jewish have never read most of the Old Testament, the vast majority of Christians have never read most of the New Testament, and the vast majority of Muslims have never read most of the Qur'an. The problem is not that people interpret their "holy books" incorrectly. The problem is that people accept other people's interpretation of those books instead of reading them and finding their own. Those who blindly follow an interpretation of a "holy book" they haven't read in its entirety and do not fully understand can be convinced to believe in dogmas which clearly run counter to their religion's founding doctrines. This is what we should be afraid of, not fundamentalism.