God Is Back: How the Revival of Religion is Changing the World

by John Micklethwait and Adrian Wooldridge

352pp, Allen Lane, £25

Buy God Is Back at the Guardian bookshop

Reason, Faith, and Revolution: Reflections on the God Debate

by Terry Eagleton

200pp, Yale, £18.99

Buy Reason, Faith, and Revolution at the Guardian bookshop

It's dismal news, and not just for secularists. God's back - and with a distinctively American drawl. Rather than religion being exiled by modernity, John Micklethwait and Adrian Wooldridge put the case that the world is moving in the American direction, where religion and modernity happily co-exist. The US separation of church and state has allowed religious entrepreneurialism to flourish. A successful new brand of Christianity is now being exported around the world. Even western Europe, held back by its legacy of established religion, will soon follow.

This isn't a book written by religionists. One a Catholic, the other of no faith, both authors work for the Economist but contritely accept their own magazine's error when it published God's "obituary" in the millennium issue. The evidence in their global survey is compelling. Even according to official figures, Christians in China now outnumber members of the communist party. The country also has 20 million Muslims - as many as Saudi Arabia, and twice as many as the EU.

Adam Smith is the new saviour: the free market has been the catalyst for expansion, with American churches now operating like multinational corporations with "pastorpreneurs" driving growth. Where modernity was supposed to bring religion's demise, democracy, markets and technology are combining to do precisely the opposite. In fact, America is contributing twice to the global revival of religion. It is not just the world's leading exporter of religion, but also the world's leading supplier of the system that increases the demand for it: capitalism.

It is surprising, therefore, that in their bold predictions the authors take little account of how the religious revival, so intricately bound up with globalisation, will fare in the new economic climate. Another significant omission, due possibly to the book's ethnocentricity, is that no reference is made to David Bebbington's seminal work, Evangelicalism in Modern Britain, which proposed that the religious revival of the 18th century in Britain could also be attributed to religion's contact with modernity.

The book's focus is a specific form of Protestant Christianity, and it will undoubtedly be criticised for making sweeping and generalised claims extrapolated from just one type of religion. But this would be to misunderstand the authors' argument that much of Buddhism, Hinduism and Islam have yet to engage with modernity (and where they have, say the authors, the hypothesis holds true).

God's return also has an integral political dimension: "Religious people are no longer content to leave their religious beliefs at home." But religious revivals are not always accompanied by political ones; the authors don't address why this one is. Nor do they acknowledge that despite no apparent increase in religious observance, a growth in Christian political activity has been observed in western Europe for more than a decade. Indeed, in both the UK and US, the radicalisation seems to have been due to a perceived decline rather than growth of religion. Christians believe the religious identity of their countries is being lost, and political action must be taken.

The authors note that the growth of evangelical Christianity has brought with it a change in the nature of religious expression, with institutionalised forms of belief giving way to everything from small house groups to megachurches. Previously, through the old, established denominations, many may have felt that religious belief had a presence in the public square. Uncertainty over unfamiliar forms could be the real driver of the new political expression; in that sense, it may not be so much a case of God being back as religion relocating.

But before secularists think the news might not be so bad after all, they should note how effortlessly, and ruthlessly, Terry Eagleton tears apart Richard Dawkins and Christopher Hitchens ("Ditchkins", as he refers to them) in Reason, Faith and Revolution. Where Micklethwait and Wooldridge set up secularism and American fundamentalism as polar opposites, Eagleton analyses their similarities. "Both parties agree pretty much on what religion consists in; it is just that Ditchkins rejects it while Pat Robertson and his unctuous crew grow fat on it."

Eagleton attacks their shared poverty when it comes to understanding Christian theology. Dawkins "falsely considers that Christianity offers a rival view of the universe to science". Hitchens makes "the same crass error ... Christianity was never meant to be an explanation of anything ... It's rather like saying that thanks to the electric toaster we can forget about Chekhov."

Eagleton carves up the "militant" atheists using their own weapons of reason. He accuses them of superstition in their belief in the march of progress; their commitment to individual freedom, he maintains, is an article of faith that has no grounding in science. His scorn is not reserved for them; it is also directed at the churches. As communism has misunderstood Marx, so Christianity has failed to embrace Christ, he says. But the criticism is mild compared to the relentless onslaught against Ditchkins, who, by the end, is left bleeding and dying.

• Jonathan Bartley is founder of the Christian thinktank Ekklesia. To order God Is Back for £23 or Reason, Faith and Revolution for £17.99, both with free UK p&p, call Guardian book service on 0330 333 6846.