A quote from Spengler at The Asia Times, 7 August 2007

Ten thousand Chinese become Christians each day, according to a stunning report by the National Catholic Reporter's veteran correspondent John Allen, and 200 million Chinese may comprise the world's largest concentration of Christians by mid-century. […] China may be for the 21st century what Europe was during the 8th-11th centuries, and America has been during the past 200 years: the natural ground for mass evangelization. If this occurs, the world will change beyond our capacity to recognize it. Islam might defeat the western Europeans, simply by replacing their diminishing numbers with immigrants, but it will crumble beneath the challenge from the East.

China, devoured by hunger so many times in its history, now feels a spiritual hunger beneath the neon exterior of its suddenly great cities. Four hundred million Chinese on the prosperous coast have moved from poverty to affluence in a single generation, and 10 million to 15 million new migrants come from the countryside each year, the greatest movement of people in history. [...] it is the great migration of peoples that prepares the ground for Christianity, just as it did during the barbarian invasions of Europe during the Middle Ages.

Last month's murder of reverend Bae Hyung-kyu, the leader of the missionaries still held hostage by Taliban kidnappers in Afghanistan, drew world attention to the work of South Korean Christians, who make up nearly 30% of that nation's population and send more evangelists to the world than any country except the United States. This is only a first tremor of the earthquake to come, as Chinese Christians turn their attention outward. [...] People do not live in a spiritual vacuum; where a spiritual vacuum exists, as in western Europe and the former Soviet Empire, people simply die, or fail to breed. [...]

The World Christian Database offers by far the largest estimate of the number of Chinese Christians at 111 million, of whom 90% are Protestant, mostly Pentecostals. Other estimates are considerably lower, but no matter; what counts is the growth rate. This uniquely American denomination, which claims the inspiration to speak in tongues like Jesus' own disciples and to prophesy, is the world's fastest-growing religious movement, with 500,000 adherents. In contrast to Catholicism, which has a very long historic presence in China but whose growth has been slow, charismatic Protestantism has found its natural element in an atmosphere of official suppression. [...]

Islam in China remains the religion of the economic losers, whose geographic remoteness isolates them from the economic transformation on the coasts. Christianity, by contrast, has burgeoned among the new middle class in China's cities, where the greatest wealth and productivity are concentrated. Islam has a thousand-year presence in China and has grown by natural increase rather than conversion; evangelical Protestantism had almost no adherents in China a generation ago.

China's Protestants evangelized at the risk of liberty and sometimes life, and possess a sort of fervor not seen in Christian ranks for centuries. Their pastors have been beaten and jailed, and they have had to create their own institutions through the "house church" movement. [...] China's network of house churches may turn out to be the leaven of democracy, like the radical Puritans of England who became the Congregationalists of New England. Freedom of worship is the first precondition for democracy, for it makes possible freedom of conscience. The fearless evangelists at the grassroots of China will, in the fullness of time, do more to bring US-style democracy to the world than all the nation-building bluster of President George W Bush and his advisers.

 
See also Fjordman’s article:

The Outcome of Two Cultural Revolutions: While China Turns Christian, Europe Turns Muslim, 14 November 2006