Not every scholarly study of early Christianity rockets to best-seller status thanks to an attack by a belligerent cable-network reporter.

But that became the fate last week of Reza Aslan's Zealot: The Life and Times of Jesus of Nazareth, just out from Random House in the United States while, in Britain, the Westbourne Press is rushing the book forward from its original August 18 publication date.

The fortunes of Zealot offer a cautionary tale for scholars who publish on touchy subjects—or perhaps a primer on how to provoke conservative-media hostility, and then to capitalize on it, even if you're no religious or intellectual radical....