LU GENGSHENG remembers growing up in rural Anhui province in the 1980s, where his father was pastor of a house church, an illegal congregation that refused to join with official churches it believed to be stooges of the Communist Party. His family owned the area’s only bible, and other believers would bring notebooks to copy passages of scripture to take home.

Today, Christians make up 5% of the population, some 67m people, according to the Pew Research Center, a think-tank. Unofficial headcounts say that China has more Christians than members of the Communist Party (about 82m people).

To meet their spiritual needs, a joint venture called Amity Printing was founded in 1988 between Amity Foundation, an NGO linked to the China Christian Council (CCC), a government body, and the United Bible Societies (UBS), a British-based group dedicated to providing access to Christian literature.

In its first year, using a single printing press donated by UBS, Amity produced 500,000 bibles. In 2012 it printed more than 12m bibles and New Testaments. This makes Amity one of the largest printers of bibles in the world; quite an accomplishment in a country where, not long ago, people died for their faith.

In 2008 the company moved to smart new premises on the outskirts of Nanjing, an affluent eastern city near Shanghai. The new factory employs 600 people and has the capacity to produce around 18m bibles a year in more than 90 languages, including English, Swahili, Zulu and Russian, as well as Braille editions. The 100-millionth bible, printed last year, is displayed proudly in the lobby.

Amity is the only publisher in China authorised to print bibles, leading to criticism that it is exploiting its monopoly status and low cost-base to make money in the export market. Indeed exports have increased and it says that roughly two-thirds of bibles printed in 2011 went overseas. Meanwhile, domestic sales have remained static, at about 4m copies per year.

Bob Fu, founder of ChinaAid, a Christian charity based in America, says Amity’s domestic quota has failed to keep up with the growth in the number of Chinese Christians. The CCC keeps a tight rein on who gets Amity’s bibles, he says, by distributing them only to 55,000 “official” churches. Though anyone can buy a bible there, Amity does not deal with the hundreds of thousands of unofficial house churches around the country. The line dividing such groups from the official churches is now less clear, but they are frequently persecuted by the government because they still refuse to register, fearing they will have to compromise their faith.

Other foreigners are trying to make up the bible deficit. Paul Hattaway, director of Asia Harvest, an American Christian group, speaks of a bible “famine” in China. In the late 1990s, he started printing bibles there illicitly. Mr Hattaway says he has distributed more than 6m of them through the house-church network.

Mr Lu, the Christian from Anhui, is now a house-church pastor himself. He says the situation is by no means perfect, but since the mid-1990s, bibles have been easier to obtain. Today every house-church member in his region owns a bible, he adds, all of them published by Amity Printing.