Compared to atheists and agnostics, Protestants are less knowledgeable of the teachings, history and figures of major world religions, a new survey reveals.

Out of 32 religious knowledge questions asked by the Pew Forum on Religion and Public Life, atheists and agnostics had on average 20.9 correct answers while Protestants as a whole answered 16 correctly.

Jews and Mormons also scored high with 20.5 and 20.3 correct answers, respectively.

When it came to Christianity, however, white evangelical Protestants were among those with the highest levels of knowledge. They scored 7.3 out of 12 on questions related to the Bible and Christianity. Mormons were the only ones to score higher, with 7.9.

Still, atheists and agnostics were not far behind with a score of 6.7.

The findings, released Tuesday, are based on a poll conducted from May 19 to June 6 among more than 3,400 Americans aged 18 and older.

The Pew Forum employed the help of Boston University professor Stephen Prothero, author of Religious Literacy, among others to design the survey and analyse the results.

Some of the questions asked included identifying: Mother Teresa's religion; the dominant religion in Pakistan; the figure who inspired the Reformation; which religion teaches that salvation comes through faith alone; and whether public school teachers can read from the Bible as an example of literature.

"[W]e could have designed harder questions, or easier ones. As it happens, through a combination of good survey design and good luck, the results were an almost perfect bell curve in which the average score was exactly half of the 32 possible correct answers, and very few people got all questions right or all questions wrong," said Luis Lugo and Alan Cooperman, director and associate director of the research.

The researchers say they have refused to give the public an "A" or "F" grade because they "have no objective way of determining how much the public should know about religion".

Nevertheless, the survey showed that Americans with a faith know little even about their own religion.

More than half of Protestants (53 per cent) cannot correctly identify Martin Luther as the person who inspired the Protestant Reformation. Forty-five per cent of Catholics do not know that their church teaches that the bread and wine used in Communion do not merely symbolise but actually become the body and blood of Christ. Forty-three per cent of Jews do not recognise that Maimonides, one of the most venerated rabbis in history, was Jewish.

Overall, at least two-thirds of respondents were able to correctly identify Mother Teresa's religion, Islam as the dominant religion in Pakistan, Moses as the man who led the exodus from Egypt, and the Constitution as stating that government shall neither establish nor interfere with religion.

Just a little more than a half know Joseph Smith was Mormon, that Ramadan is the Islamic holy month, that the Koran is the Islamic holy book, and that the Golden rule is not one of the Ten Commandments.

Forty-seven per cent know that the Dalai Lama is Buddhist and only 45 per cent know the four Gospels are Matthew, Mark, Luke and John.

Less than a third are knowledgeable about Jonathan Edwards participating in the First Great Awakening and know that Protestants traditionally teaching that salvation comes through faith alone.

Most were able to correctly answer at least half of the survey's questions asking them to identify the first book in the Bible and where was Jesus born.

Measured on their knowledge of religion in public life, 89 per cent knew public school teachers cannot lead class in prayer but only 23 per cent knew that teachers can read from the Bible as an example of literature.

Notably, the Pew Forum found that college graduates get nearly eight more questions right on average than people with only a high school education or lower. Those who read Scripture at least once a week, talk about religion with friends and family, and have high levels of religious commitment also are likely to score higher.

Those with the lowest scores on the religious knowledge survey include Hispanic Catholics, black Protestants and Americans who describe their religion as "nothing in particular".

The survey was an attempt to provide a baseline measurement of how much Americans know about religion today.

Researchers note that they cannot conclude whether Americans in 2010 know more or less about religion than prior generations did because of the lack of historical data on levels of religious knowledge among Americans.