China is in the grip of 'one of the world's great spiritual revivals', Pulitzer-prize winning author Ian Johnson is claiming.

Global powers should take note of this 'spiritual transformation', he says, because it could have global repercussions.

'People are looking for new moral guideposts, some sort of moral compass to organize society,'writes Johnson, in an article for The Atlantic.

'So they are turning to religion as a source of values to help reorganize society.'

The drivers of this 'religious revolution' are Christian house churches which are unregistered and disapproved of by the Chinese state.

'These groups have become surprisingly well-organized, meeting very openly and often counting hundreds of congregants,' hewrites.

'They've helped the number of Protestants soar from about one million when the communists took power to at least 60 million today.'

Although the Chinese Communist Party is still deeply opposed to the rapid growth of underground churches, it hasn't stopped people exploring faith.

'Any casual visitor to the country can tell you that the number of churches, mosques, and temples has soared in recent years, and that many of them are full," Johnson writes.

'While problems abound, the space for religious expression has grown rapidly, and Chinese believers eagerly grab it as they search for new ideas and values to underpin a society that long ago discarded traditional morality.'

He adds: 'Hundreds of millions of Chinese are consumed with doubt about their society and turning to religion and faith for answers that they do not find in the radically secular world constructed around them.'