A new study by the Pew Research Center’s Forum on Religion & Public Life shows that atheists and agnostics have the best religious knowledge. Atheists on average answered 20.9 of 32 religious knowledge questions correctly. Judaism (20.5 correct) and Mormonism (20.3) came in second and third, respectively. Although non-believers came in first in general religious knowledge, Jews got first place for knowledge of world religions and second place for knowledge of religion in public life. One surprising finding, although white evangelicals and Mormons knew the most about the Bible and Christianity, atheists and agnostics were the third-highest. So even though they don't practice Christianity, according to this particular study, atheists know more about the Bible than Catholics, mainline Protestants, and Jews.
"Atheists/agnostics and Jews stand out for high levels of knowledge about world religions other than Christianity," the study said, "though they also score at or above the national average on questions about the Bible and Christianity." The study found highly educated people know more about religion than the less educated, and Jews and agnostics/atheists were more likely to have a high level of education. But even controlling for education, those two groups had better scores than those of other faiths.
Atheists only make up about 3% of the US population, but according to a 2010 Gallup poll, they're one of Obama's most supportive "religions" at 63%, after Muslims (78% support Obama) and non-Christians (64%). Obama's performance has declined among all religious groups since January 2009, but it's decreased least among Muslims. The Pew study couldn't find enough American Muslims to include in its study, so at present, it's not clear what their level of religious knowledge is versus other religious groups. One can only hope they, unlike tea partiers and an estimated 20% of the US, know Obama isn't actually Muslim.