This past week, the Associated Press published a story based on its analysis of leaked Islamic State (ISIS) recruitment documents. These documents indicate that, based on the recruits' own self-evaluation, most ISIS recruits have only a basic knowledge of Islam. Some have argued that these "findings suggest religion has nothing to do with people joining [ISIS]."
That argument is seriously flawed. It rests on a faulty premise, namely that one needs to be thoroughly familiar with a religion's doctrines to be motivated by that religion to engage in violence or embrace extreme positions on moral, legal, and political issues. There is no support for this premise.
Protestants and Catholics slaughtered each other for a couple of centuries in early modern Europe. Were all the Catholics who took part in or supported such violence able to explain transubstantiation, the treasury of merit, the role and effect of the various sacraments, apostolic succession, and the invocation of saints? Although we don't have surveys from 1550, somehow I doubt it.
Ignorance of the doctrines of one's own religion continues today, across the board. A 2010 Pew Research Center survey found that only 16% of American Christians are familiar with a core doctrine of Protestantism, namely that salvation comes from faith alone. (Interestingly, this same survey shows that atheists know more about religious doctrines and religious history than the religious.) This failure to grasp a key precept of their faith has not prevented many fundamentalist Protestants from insisting that their Christian faith should be the basis for determining what is legal and illegal in the United States.
Detailed knowledge of the doctrines and rules of a particular religion has always been the province of the clerical class, not of the mass of believers. Most people don't have the inclination or interest to delve into the intricacies of religious doctrines or to memorize the myriad restrictions on personal behavior in which religions specialize. They leave such matters to the priests, rabbis, and imams of the world, who tell the faithful what to eat, what to drink, what to wear, how to pray, and so forth.
So extensive knowledge of a religion's doctrines is not necessary to be committed to and motivated by a religious belief. And please don't say, "ISIS terrorists are perverting Islam; what they practice is not true Islam." There is no such thing as true Islam, true Christianity, true Judaism, or true Mormonism. All these religions are based on sacred texts which admit of a wide variety of interpretations. One can find a verse in the Bible or Qur'an to justify just about anything. ISIS propaganda is replete with quotes from the Qur'an. And their interpretation of the Qur'an is perverted because ... because someone else has a different interpretation of the Qur'an? Who arbitrates that dispute?
Of course, Muslims who support terrorism are very much a minority--albeit far from an insignificant minority. There are many factors other than religious belief that can play a role in causing someone to support terrorism, including social isolation, a sense of disenfranchisement, and so forth. But it's a mistake to exclude religious belief as a factor. It doesn't matter whether the person knows the details of The One True Belief as long as they are committed to The One True Belief. Far too often in human history, those committed to The One True Belief have viewed individual human lives as unimportant when compared to the greater glory of God.
Christians have, for the most part, stopped killing each other and those of other faiths for the greater glory of God. This wasn't because in the 1700s someone found some hitherto overlooked verse in the Bible that said "Hey, don't do that." No, it's due in large part to the secularization of Europe and the Americas that followed the Enlightenment. More and more people accepted the view that religious belief, or lack thereof, is a private matter, and the government should stay out of religious affairs and vice-versa. Although some in the United States still think we should look to the Bible for guidance in deciding what laws we should have, most people now realize that given all the different and inconsistent ways holy scriptures can be interpreted, religion has no role to play in public policy disputes. We can't look to God to tell us what to do. We need to talk to each other and figure that out for ourselves. Until a similar secular mindset gains wider acceptance in the Muslim world--until most Muslims stop quoting the Qur'an for justification for this policy or that policy--there will be those who will want to promote The One True Belief by any means necessary.