Letter from China/ Pat Comerford: As China becomes the world's fastest-growing capitalist economy, Chinese society is also experiencing growth in other areas - this is world's fastest-growing market for mobile phones, and an increasing number of children are facing eating-related disorders such as obesity.
But a more phenomenal growth is the rapid rise in the number of Christians.
According to the latest figures from the Amity News Service, there were over 18 million Protestants in China in 2004, a one million increase on the figure for the previous year. With at least 12 million more Catholics, the most conservative estimates say there are at least 30 million Christians in China, but more optimistic estimates put the figure at 80 million or more.
With many Christians belonging to unrecognised or so-called "underground" churches, it is impossible to verify these figures. But no one denies the current astounding growth in Christianity in China.
When Mao's Communists came to power in 1949, China had less than a million Protestants and about three million Catholics. But over the last two decades, the mainstream Protestant Church has opened three new places of worship every two days, church building continues at a rapid pace in every province and region, and the Amity Printing Press in Nanjing has printed an average of two million Bibles each year since 1987.
The dividing line between the mainstream and "underground" churches is becoming blurred, with church leaders using the term "meeting place" to describe outlying church plants, often with hundreds of members, using rented, unregistered premises but identifying with the larger churches in the towns and cities.
The largest church in China today is Chong-Yi church in Hangzhou (Hangchow), a city of 6.5 million people south of Shanghai. Bishop John Curtis of Zhejiang (Chekiang), a former Irish soccer international who lived in Hangzhou, was one of the last Anglican missionaries to leave China in 1950. He could have hardly imagined the rapid church growth in Hangzhou half a century later.
Chong-Yi church, with seating for more than 5,000 people, was dedicated last May. On a recent Sunday, about 2,500 people took part in the main service, with over 2,000 receiving Holy Communion.
Further south, I attended the opening of the new Guizhou Bible School. Over 3,000 people were present for the opening ceremony in Guiyang, the capital of Guizhou Province and a city of over 3.5 million people.
The school was the brainchild of Pastor Samuel Tang, a rural doctor who has funded the training of pastors, evangelists and lay leaders from his earnings at his clinics.
Out in the mountains of remote provincial Guizhou, I found one of the many rural churches benefiting from the Pastor Tang's vision. It takes four hours by private transport to reach the mountain-top village of Haima. The people belong to the Miao ethnic minority, and it takes the villagers of Haima as long to travel to Beijing by public transport as it took me to fly from Dublin to Beijing. But this distant village has a church dating back to the early 20th century, and all 700 villagers are said to be church members.
In Shanghai, as part of the government response to the surge in support for Christianity, the former Anglican cathedral on Jiujiang Street has been handed back to the church after almost six decades of use as a theatre and cinema. After colonial rule in Shanghai came to an end in 1949, the cathedral choir school was used as a police station and visa office.
But in the past year the former school has been refurbished as the new headquarters of the China Christian Council and the Three-Self Patriotic Movement, the official state-recognised Protestant church in China.
There is an officially-recognised Catholic Church, but in the past its adherents were not allowed to recognise the pope's authority. Everyone agrees the official figure of 12 million vastly underestimates the real number of Catholics in China.
But if China's Catholics were divided in the past between the state-recognised Patriotic Catholic Association and the so-called "underground" church, Chinese Catholics were united earlier this year in mourning Pope John Paul II, who never achieved his life-long ambition to visit China.
In recent years, the Patriotic Catholic Association, established in 1951, and the "underground" Catholic church, which continued to maintain loyalty to Rome, have moved ever closer to one another.
In Shanghai's Xujiahui Cathedral last June, Bishop Joseph Xing Wenzhi (42) was consecrated Auxiliary Bishop of Shanghai, China's largest Catholic diocese, by Bishop Aloysius Jin Luxia. The ailing Bishop Jin (89), who spent 29 years in labour camps and in prison, has been the state-recognised Bishop of Shanghai since 1985.
But Bishop Xing's appointment as his successor has the approval of both the state and the Vatican, with the Vatican indicating it will not appoint a successor to the unofficial or "underground" Bishop Joseph Fan Zhongliang. Similar consecrations in the dioceses of Zhengding and Hengshui show the boundaries between the official and unofficial church are becoming blurred and vary from area to area, as does the attitude of local governments towards the two expressions.
On the other hand, it may take decades to heal the divisions between China's Protestants and Catholics, who often see each other as members of two different religions.
The search for unity may become increasingly important as the church in China faces a new future. In the past, it learned with difficulty to live alongside the Red Flag; now it may be facing new difficulties as it adapts to living alongside the secularism and commercialism that come with capitalism and rapid economic growth.
• Rev Patrick Comerford is a Church of Ireland priest and has been travelling throughout China with a delegation representing churches and mission agencies in Ireland, Britain and Germany.