Fundamentalism is perhaps one of the most misunderstood words in the American lexicon. Its negative connotation conjures images of religious radicals, extremists, and anti-intellectuals.. Critics of Fundamentalism like Karen Armstrong, Bruce Bawer, and John Shelby Spong often develop their own criteria to define the ideology, which usually has less to do with fundamentalist beliefs and more to do with their positions on science, abortion, and sex. Ironically, some people consider themselves not to be fundamentalists simply because they take relaxed stances on issues like abortion and gay marriage, when theologically they are still very much fundamentalist in their beliefs. An unusual phenomenon is that Christian fundamentalists may become skeptics after being unable to reconcile an unreasonable Biblical literalism, essentially retaining fundamentalist interpretive methods even as nonbelievers. More recently, the term has been extended to people of other religions in addition to Christianity, as if it were an all-encompassing ideology that could be applied in equal measure to any belief system. This, however, is a misnomer that only creates further confusion about the definition of a fundamentalist.
The first problem with calling members of other religions “fundamentalists” is that fundamentalism is a term specifically coined to refer to Christians who subscribed to the “Five Fundamentals” (Biblical inerrancy, virgin birth, substitutionary atonement, bodily resurrection, and the reality of miracles), a theological package which is exclusively Christian. The second problem is that Fundamentalism was a reactionary ideology to the emerging Modernist and liberal schools of the 19th century. Other religions that have acquired a label of “fundamentalist” by some adherents have not even yet had such an encounter with Modernism. For instance, Islam has no comparable school of textual criticism of the Qur’an as there exists for the Bible, while their beliefs about revelation differ tremendously from the Christian concept of inspiration, its closest comparison is to Biblical inerrancy. There is no organized body in Islam that dares to question the virgin birth, and while the atonement and resurrection of Christ are rejected by the Qur’an, these beliefs are absolutely held in common by all Muslims. In other words, if we were going to apply the same definition to Islam, we would be forced to conclude that all Muslims are fundamentalists, not just the Ayatollah or Al Qaeda.
Similarly, Mormonism includes a splinter sect called the Fundamentalist Church of Jesus Christ of Latter-day Saints, but the line of demarcation between them and mainline Mormons is the continuation of beliefs from the time of Brigham Young, namely polygamy. Like Islam, Mormonism has a long history of rejecting textual criticism and non-literal interpretations of the Book of Mormon and other later scriptures (although, ironically they employ peculiar, unscholarly criticism of the Bible). Proponents of theories suggesting the Book of Mormon is inspired folklore, for instance, have resulted in reprimanding and disciplinary action. In essence, all Mormons subscribe to a fundamentalist worldview, whether they see it that way or not. Like some Christians, they may even entertain evolutionary theory as possibly compatible with their scriptural beliefs, but they still do so on fundamentalist terms (it may shock many of today’s Christians to discover that the essays in “The Fundamentals” did not actually denounce biological evolution). I would go so far as to say Mormons and Muslims could not possibly relate to a non-fundamentalist worldview and still believe in their religion, because textual criticism would naturally unravel it.
It’s clear that not all Fundamentalism is created equal. While generally a best practice is not to refer to any group as fundamentalist unless they take that title for themselves, even among those who make that claim it is evident that their reasons for calling themselves such, like fundamentalist Christians and fundamentalist Mormons, are completely dissimilar. Ironically, when apologists try to defend a religion like Islam from criticism about jihad or human rights violations, suggesting that fundamentalism is the problem, not the religion itself, they would technically be categorically denouncing their entire religion anyway if they honestly applied the term the same as they do to Christianity.