Religion in China. That was the topic of a recent excellent Economist article. Here is one good excerpt:
It is hard even to guess at the number of Christians in China. Official surveys seek to play down the figures, ignoring the large number who worship in house churches. By contrast, overseas Christian groups often inflate them. There were perhaps 3m Catholics and 1m Protestants when the party came to power in 1949. Officials now say there are between 23m and 40m, all told. In 2010 the Pew Research Centre, an American polling organisation, estimated there were 58m Protestants and 9m Catholics. Many experts, foreign and Chinese, now accept that there are probably more Christians than there are members of the 87m-strong Communist Party. Most are evangelical Protestants.
Predicting Christianity’s growth is even harder. Yang Fenggang of Purdue University, in Indiana, says the Christian church in China has grown by an average of 10% a year since 1980. He reckons that on current trends there will be 250m Christians by around 2030, making China’s Christian population the largest in the world. Mr Yang says this speed of growth is similar to that seen in fourth-century Rome just before the conversion of Constantine, which paved the way for Christianity to become the religion of his empire.
In the 1980s the faith grew most quickly in the countryside, stimulated by the collapse of local health care and a belief that Christianity could heal instead. In recent years it has been burgeoning in cities.
Read the whole thing. You will note that when individuals engage in a “portfolio” approach to religion, social evolution can occur much more rapidly. Not everyone has to fully convert to Christianity, or to embrace Confucianism wholeheartedly, for those approaches to suddenly acquire much more influence.