The trend has caught the attention of the BBC. Writing in the BBC News Magazine, Denise Winterman reports:
Births, deaths and marriages. They're the only events that get most people in the UK through church doors these days and even that is too often for some.
But this doesn't stop the majority of us calling ourselves Christian. More than half of British people say they believe in God despite only one in seven actually attending a Christian church service each month, says a new study.
It seems that while people find the church thing a little bit difficult, they are willing to recognise God. There's even a cute catchphrase for this absent majority - believing without belonging.
"Believing without belonging" is indeed a catchphrase, but there is no reason for confidence that the "believing" here has anything to do with biblical Christianity.
More from the BBC report:
In today's "post-modern society" people want everything on their own terms - that includes Christianity, says Dr Elaine Storkey, a Christian academic, broadcaster and president of Christian charity Tearfund, which commissioned the study.
"People are used to instant gratification, they are used to having what they want, when they want and without putting in too much effort. Some view religion in the same way."
Having a connection with Christianity is not a problem for most people, it's when something is asked of them that they start to struggle, she says.
"The first step to get people involved in the church is getting them to consider God. A lot of people identify with Christianity even if they don't attend church. Often when the chips are down they fall back on the Christian faith.
"The second step is getting them to consider how much their faith will cost them. That's a huge leap for most people, that's when they have to start giving something back."
Some sort of "vague Christianity" acts as a way for people to keep their options open, they don't have to think too hard about life and aren't pushed outside their comfort zone, says philosopher Dr Julian Baggini.
"It's easier than going in the other two directions. If you take religion fully on board you have to believe some strange things. Discarding it totally means you have to really think through the consequences, that death really is the end and many people find that worrying."