Fewer people consider themselves Christians than 25 years ago, according to new analysis of 2008 data, but social commentators say there may be more committed Christian believers.
The analysis comes from the 2008 British Social Attitudes Survey and shows 50 per cent of people say they are Christians, down from 66 per cent in 1983.
However Ed West, writing on his blog on The Daily Telegraph website, points to Evangelicalism rising in the UK among African migrants and British-born Christians.
And George Pitcher, a Daily Telegraph columnist and Anglican minister, says that people are now “voluntarily and thoughtfully” signing up to Christianity.
The new analysis says the proportion of Britons who say they have “no religion” has increased from 31 per cent to 43 per cent.
It also shows that the decline in “institutional religion” may be down to the fact that fewer children are being brought up in a particular religion.
Prof David Voas, who studied the data, commented: “The results suggest that institutional religion in Britain now has a half-life of one generation, to borrow the terminology of radioactive decay.
“Two non-religious parents successfully transmit their lack of religion. Two religious parents have roughly a 50/50 chance of passing on the faith.
“One religious parent does only half as well as two together.”
Prof Voas also highlighted what he called the “fuzzy faithful”, 36 per cent of people who “identify with a religion, believe in God or attend services, but not all three”.
Prof Voas said the declining Christian share is “largely attributable to a drift away from the Church of England”. That figure is down from 40 per cent of those who call themselves Christians to 23 per cent.
Ed West, describing his experience of an evangelical church service, said: “Evangelicals, whether anyone likes it or not, believe, and it shows.
“Doubt and scepticism are fine things but a religious community that does not believe in its own message will wither and die, and be replaced by others.”
In June a survey showed moral decline is damaging British society and even some atheists think a loss of Christian values is to blame.
Moral decline was one of seven social evils identified by a survey of 3,500 people in Britain by the Joseph Rowntree Foundation (JRF).
The report also identified greed, family breakdown and poverty as blights on British society.
The study found “it was not only people with religious beliefs who recognised the impact of a decline of religion on our values”.
One atheist respondent said that a “decline in belief in Christianity has unhinged people’s moral compass”.