I'll leave it to theologians and religious leaders to decide whether God cares about the ignorance of worshippers, so long as they remain worshipful, or if knowledge of religious practices and beliefs is necessary to salvation. I'm interested in the political implications of religious ignorance in this very religious country.

It seems obvious that ignorance like this enhances bigotry. The less people know about Islam the more likely they'll take on faith the ravings of Islamaphobes like Pam Geller. A little less obvious, and surely less noticed, is the corrosive effect of misinformation about unpopular or demonized religions on civil liberty. Muslims may be most directly effected by post 9/11 abuses, ranging from torture and summary detentions to secret blacklisting, but imbuing the government with unaccountable power to engage in these practices poses clear and present dangers to everyone's liberty.

Religious chauvinism flourishes along with bigotry when ignorance reigns: The less you know about other people's religions, the more blithely you may assert the superiority of your own, especially if you're also unfamiliar with its teachings; unfamiliarity with your own faith will not incline you to criticize its failings. Un-informed religious sanctimony is perhaps most evident in hostility toward atheists and agnostics who are routinely accused of lacking any moral compass (unlike, say, pedophile priests and the bishops and cardinals who covered for them). People are entitled to their prejudices (and, personally, I don't care if religious people assume I lack a conscience). But the bias against non-believers ensures their political under-representation. When large majorities demand that congressional candidates display strong religious beliefs, atheists or agnostic are less likely to seek office. Those who do, are apt to lie low or simply lie about their irreligiosity, like members of the military forced to hide their sexual identities.

It's impossible to quantify the effect of these religious superiority complexes on church/state separationism, but recent increases in government support for sectarian religious groups are undeniable. Some support is direct, pursuant to faith based initiatives popularized by the Bush administration; some is indirect, in the form of exemptions from general laws enjoyed by religious groups even when they engage in secular or commercial activities. Besides, public ignorance of religion is matched by ignorance of constitutional principles governing church/state relations. According to Pew's religious knowledge survey, only a little over a third of Americans understand that public schools may offer courses in comparative religion; a mere 23% know that teachers may "read from the Bible as an example of literature."

Small misunderstandings like this can be highly consequential: They promote unwarranted hostility toward secular government, based on mistaken assumptions about its hostility toward religion. No wonder so many people regard separation of church and state as a burden on religious expression, instead of an instrument of religious freedom (especially essential to minorities). It includes the freedom to learn -- if only majorities would take advantage of it.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.