Atheists and agnostics scored the highest, with an average score of 21 correct on the 32-question survey. Jews and Mormons both averaged about 20 correct answers, while Protestants averaged 16 correct answers and Catholics averaged 15. Atheists, agnostics, and Jews also knew the most about other faiths. Questions ranged in difficulty, from the name of the first book of the Bible, to what century the Mormon religion was founded. People who said they attended worship once a week or more tended to score higher, as did those with higher levels of education.
I might hazard that for whatever this little survey is worth (we all know statistics are the work of the devil; long form census anyone?), that the religions with the more ignorant poorly informed followers tend to bray the loudest about the dangers of other [non-]faiths and the merits of their own.