China is also facing an enormous migrant problem as China's population quickly moves from 80-20 percent rural to 80-20 percent urban. Most newcomers to cities live in poverty: Often embittered, can't crawl home, but their pent-up grievances could lead to a violent explosion unless Christians, like the British Methodists of the 18th century, pave the way to a peaceful transition to a fully industrialized society.

Maybe some officials even realize that Christians like Pastor Gao (also not his real name), whom they used to jail, are also helpful, even though he operates an illegal seminary dedicated to teaching migrants. Gao and others teach theology, English, computers and music to 26 students, some of them still teenagers, who squeeze into five small bedrooms of two run-down apartments with old bicycles and part of a kitchen sink outside.

Gao's grandfather when young was a disciple of famed missionary Hudson Taylor, who died in China in 1905. Mr. Gao became a Communist Party member but he listened to radio broadcasts from other countries, began to read the Bible seriously, and prayed to "the God of my grandfather."

Those like Gao who believe in a Savior may turn out to be the salvation of China and of the world. As China becomes an economic and military superpower over the next several decades, the ascendancy of aggressive and xenophobic leaders will be a recipe for war -- but the impact of hundreds of millions of Chinese Christians will be immense.