ON THE LAGOS-IBADAN EXPRESSWAY, Nigeria — For many, this highway leads to the future of the Christian faith, and at 9 o'clock on a Friday night, traffic is heavier than a Los Angeles rush hour.
Hundreds of thousands of Nigerians, from street vendors to computer consultants, sit through the exhaust and the squealing horns to reach evangelical campgrounds with churches as large as airplane hangars. The names are as spectacular as the hopes they sell: Mountain of Fire and Miracles, Deeper Life, and the largest and oldest, the 12,000-acre Redemption Camp.
The worshipers are drawn by a program of rousing song and dance and by an eminently practical gospel promising health and prosperity. They come seeking quick fortunes or protection against mundane maladies, from hunger to arthritis to armed robbers. They shout hallelujahs until close to daybreak, when the highway, famous for accidents and bandits,...