"religious fundamentalism". Bad term. Religion is based on "beliefs".
The meaning of "belief" is "a feeling that something exists or is true, especially one without proof."
So only a fool would "Believe" or entertain "beliefs".
"Beliefs" sow the seed of fundamentalism. Some "M" appears in India and say that caste should be birth-based. Someone appears outside India and say he has been sent down by Almighty and humanity should be divided as believers and non-believers and only what I say is true.
A believing mind is the fertile field in which charlatans sow seeds of religion by claiming taht they r divine. They tell big lies(people r accustomed only to telling small lies). When they hear a big lie, they "believe" it.