CLOSE your eyes and think of Christianity in Britain: especially if you don't have much contact with the real thing, images of village fetes, ancient stone chapels and settled communities in genteel but unnoticeably slow decline may still come to mind. They fit in with a certain rose-tinted vision of Britain itself, to which Britons and Anglophiles cling, even though they know perfectly well that far more people live within sight and earshot of a motorway than in cottages surrounded by tweeting songbirds. You may have noticed that the latest edition of _The Economist_, in [one of its cover illustrations](http://www.economist.com/printedition/covers/2015-02-19/e-eu- me-uk), teasingly inserts an image of an archbishop in a green and pleasant but fissiparous English landscape. As recently as 20 years ago, says one of the country's eminent religion- watchers, that stereotype did have some relationship with reality. The practice of Christianity was stronger in suburbs, small towns and villages than in big cities, and it was disproportionately middle-class. The Church of England had things to say about the problems of urban poverty (it annoyed Margaret Thatcher in 1985 with a left-leaning document called "Faith in the City") but not many people in those blighted conurbations ever darkened its door. But now, says Grace Davie, a sociology professor at Exeter University, the picture has completely changed, in ways that nobody could have foreseen in 1994 when she brought out the first edition of her [book](http://www.amazon.co.uk/Religion-Britain- Since-1945-Contemporary/dp/0631184449) "Religion in Britain since 1945: Believing without Belonging". The position of Christianity (as measured by church-going, rites of passage and answers to opinion polls) has suffered steady though not yet catastrophic decline in its presumed strongholds: rural areas with a settled population, schools favoured by the middle class, and so on. But church-going in London, along with the practice of many other religions, has risen quite sharply. In a new and [massively revised version](http://eu.wiley.com/WileyCDA/WileyTitle/productCd-1405135964.html) of her work, Ms Davie says she has to take account of the "huge religious market- place" which London has become. Other observers have noticed this. A [survey](http://www.brierleyconsultancy.com/images/londonchurches.pdf) of greater London by the Brierley Consultancy, published in 2013, found that since 2005, average church attendance in the capital had risen from 620,000 to 720,000, and the number of places of Christian worship had grown by 17% to 4,800. That is despite the fact that the share of self-described Christians among London's population fell from 58% in 2001 to 48% in 2011; the proportion of those Christians who attend church must have gone up significantly. But it would be misleading to ascribe this to a sudden revival in conventional Anglican worship; the established church still has far more buildings than it can fill, and the era of Victorian piety, when many of those churches went up, will hardly come back. The real driver is London's emergence as a world city, where nearly 40% of the population was born outside Britain. Religion in the metropolis is less affected by trends in Europe (where Christianity is historically privileged but losing its grip) and more by trends in the world, where Christianity is shifting southwards and in favour of exuberant forms of worship such as Pentecostalism. The upsurge in London's Christian practice takes many different forms, from Catholic masses in Tagalog (the tongue of the Philippines) and Polish to Pentecostal gatherings in Brazilian Portuguese and many other tongues. Black- majority churches, from Caribbean evangelicals to charismatic Africans, account for a big share of the rise. American-style church planting, with a conservative evangelical ethos, has had some success among middle-class professionals. Christianity's unconventional flourishing in London isn't merely a function of high immigration; another factor is the vibrancy of the London economy, which means that a church that owns even a tiny piece of property can support itself by renting it out. It remains to be seen how this gloriously diverse new Christian constituency will respond to the latest, semi-political [pronouncement](https://www.churchofengland.org/media/2170230 /whoismyneighbour-pages.pdf) from the bishops of the Church of England, which without endorsing any political party urged people to exercise the vote in the forthcoming election; it also advocated a "living wage", questioned the logic of nuclear deterrence and called for "structures of co-operation and trust" in Europe. Unfortunately many potential recipients may be too busy trying to earn that living wage and send part of it home to Africa or the Philippines to have much time to read church missives.