Atheists are coming out of the closet. Today, some 5 million Americans claim to be atheists. Throw in agnostics and you have 20 million. Five books making the case for atheism have become bestsellers. The 9/11 attacks have sparked a backlash against "fundamentalism" of every sort, painting conservative Christians with the same brush as Islamofascists. Atheists would seem to be poised for growth, but they have a public-relations problem. A University of Minnesota poll last year found that atheists were America's most distrusted group. According to a recent Newsweek poll, 62 percent of Americans would refuse to vote for an...