Want to know about God and religion? Ask an Atheist!

If you want to know about God, you might want to talk to an atheist.

Heresy? Perhaps. But a survey that measured Americans' knowledge of religion found that atheists and agnostics knew more, on average, than followers of most major faiths. In fact, the gaps in knowledge among some of the faithful may give new meaning to the term "blind faith."

A majority of Protestants, for instance, couldn't identify Martin Luther as the driving force behind the Protestant Reformation, according to the survey, released Tuesday by the Pew Forum on Religion & Public Life. Four in 10 Catholics misunderstood the meaning of their church's central ritual, incorrectly saying that the bread and wine used in Holy Communion are intended to merely symbolize the body and blood of Christ, not actually become them.

Atheists and agnostics — those who believe there is no God or who aren't sure — were more likely to answer the survey's questions correctly. Jews and Mormons ranked just below them in the survey's measurement of religious knowledge — so close as to be statistically tied.

So why would an atheist know more about religion than a Christian?

American atheists and agnostics tend to be people who grew up in a religious tradition and consciously gave it up, often after a great deal of reflection and study, said Alan Cooperman, associate director for research at the Pew Forum.

"These are people who thought a lot about religion," he said. "They're not indifferent. They care about it."

Atheists and agnostics also tend to be relatively well educated, and the survey found, not surprisingly, that the most knowledgeable people were also the best educated. However, it said that atheists and agnostics also outperformed believers who had a similar level of education.

The groups at the top of the U.S. Religious Knowledge Survey were followed, in order, by white evangelical Protestants, white Catholics, white mainline Protestants, people who were unaffiliated with any faith (but not atheist or agnostic), black Protestants and Latino Catholics.

Muslims, Hindus and Buddhists were included in the survey, but their numbers were too small to be broken out as statistically significant groups.

Stephen Prothero, a professor of religion at Boston University and author of "Religious Literacy: What Every American Needs to Know — And Doesn't," served as an advisor on the survey. "I think in general the survey confirms what I argued in the book, which is that we know almost nothing about our own religions and even less about the religions of other people," he said.

He said he found it significant that Mormons, who are not considered Christians by many fundamentalists, showed greater knowledge of the Bible than evangelical Christians.

The Rev. Adam Hamilton, a Methodist minister from Leawood, Kan., and the author of "When Christians Get it Wrong," said the survey's results may reflect a reluctance by many people to dig deeply into their own beliefs and especially into those of others.

"I think that what happens for many Christians is, they accept their particular faith, they accept it to be true and they stop examining it. Consequently, because it's already accepted to be true, they don't examine other people's faiths. … That, I think, is not healthy for a person of any faith," he said.

The Pew survey was not without its bright spots for the devout. Eight in 10 people surveyed knew that Mother Teresa was Catholic. Seven in 10 knew that, according to the Bible, Moses led the exodus from Egypt and that Jesus was born in Bethlehem.

The question that elicited the most correct responses concerned whether public school teachers are allowed to lead their classes in prayer. Eighty-nine percent of the respondents correctly said no. However, 67% also said that such teachers are not permitted to read from the Bible as an example of literature, something the law clearly allows.

For comparison purposes, the survey also asked some questions about general knowledge, which yielded the scariest finding: 4% of Americans believe that Stephen King, not Herman Melville, wrote "Moby Dick."