When it comes to describing the end of the world, millions of readers are convinced that the "Left Behind" books contain the gospel truth.

This isn't surprising since these 12 novels -- backed by sequels, movies, video games and comic books -- have sold 70 million copies. For most readers, the page-turners cranked out by writer Jerry Jenkins and preacher Tim LaHaye form a pop-culture catechism that explains some of the Bible's most mysterious passages, said researcher Robert Woods of Spring Arbor University.

But a recent survey of "Left Behind" readers did yield one big surprise. While nearly 69 percent were, as expected, evangelical and mainline Protestants, 8.6 percent of the readers were Catholics and the remaining 22.8 percent said they practiced Islam, Judaism, Buddhism or another world religion. Why did they dig into these books?

"Curiosity was a big reason," said Woods, who teaches communications at the evangelical campus in Michigan. "It also seems that many of them thought that by reading these books they could learn about

Christianity. ... So now they think that what the 'Left Behind' books teach is what ordinary Christians believe about the end times."

For many non-Christians, he said, the words "Left Behind" and "Christianity" are now tightly linked. They have been fed a pop version of "premillennial dispensationalism," a complicated 19th Century doctrinal system that says Jesus will reign for 1,000 years on earth after the last trumpet sounds, the dead rise and the true Christians are "raptured" to meet Christ in the air.

Many Christian leaders will find this disturbing. This is especially true since there is a born-again believer in the White House and the daily news is full of explosive headlines about the Middle East, the

tense region that dominates the apocalyptic plots in these novels.

"I don't want people to pigeonhole the Protestant view of the end times," said Woods. "But you know, there are lots of people who, if you tell them you are an evangelical, then they are immediately going

to say, 'That means you're one of those Pat Robertson, Jesus freak Christians.' Now there are people who, if you say you are an evangelical, they are going to say, 'Oh, you're one of those 'Left Behind' Christians.' "

The Spring Arbor team -- Woods, Kelly Skarritt and statistician Caleb Chan -- began with a 33-item survey that was posted at the official Tyndale House website used to promote the "Left Behind" series. This invitation drew 16,916 voluntary responses. The researchers then did an in-depth, random study of 1,312 readers drawn from this larger flock.

Once again, many of the results were predictable. No one was surprised -- because of previous research by evangelical pollsters -- that the typical "Left Behind" reader is a female, married, white,

evangelical, politically conservative, Bible-Belt resident who is between 30-something and 50-something and who goes to church almost as often as she consumes Christian mass media.

On the other side of this divide were those least likely to appreciate the fiction of LaHaye and Jenkins. These readers were more likely to be male, single, black or Hispanic, politically progressive and residents of the American West or Northeast.

However, most of the readers -- their denominational ties didn't matter -- said they believe that the "Left Behind" books are highly accurate portrayals of what the Bible teaches about the end of the world or, at least, the beliefs of conservative Christians about that subject.

When readers were asked about their motivations, the most intense clusters of responses came from those who affirmed that they read the books in order to compare what they "say about the 'end times' with what the Bible says" or because the series explains the "events described in the book of Revelation in an understandable way."

The goal, said Woods, is to do more research into why so many non-Christians read the "Left Behind" series and the impact the books had on their beliefs.

"Most forms of Christian entertainment just 'rock the flock' that already lives in our gospel ghettos," he said. "But it does seem that this form of media -- apocalyptic fiction -- is reaching some new people in our post-9/11 culture. It appears that there really are people out there who are curious about ultimate issues. We may be on the verge of another wave of rapture culture."