Several years ago, Romani Prodi, then EU president, received some unsolicited advice about the UK's 2001 census. According to one of his senior advisors, a British anti-religious group wrote telling him to ignore the results of the religious question on the Census. Prodi and his advisor were baffled, not having considered the question until then. Fortunately, the anti-religious intervention had brought it to their attention and they subsequently studied the results with interest.
Religious statistics, like religion itself, has become something of a battleground in modern Britain. The nation is now officially post-Christian because "only" four million people attend church on an average Sunday. (Of what other weekly activity do we use the word "only" when talking about four million people?)
Britain remains thoroughly Christian because 37 million people put Christian in the national census (which begs the question where 90% of them are on a Sunday morning).
Britain is fast becoming a Muslim nation because "there will be fewer people attending churches than mosques by 2040" (let's ignore the dubious assumptions built into this forecast).
Britain is a basically secular nation because over a third (36%) of the British population has "a Humanist outlook on life" (whatever that is).
In reality, religious research is a messy and indecisive affair because religion is a messy and indecisive affair.
The problems of defining what religion actually is are legion. Just as it is impossible to define one thing that distinguishes humans from other animals and we do better to talk about a cluster of factors (language, tool use, rationality, etc), so religion cannot be reduced to one measurable factor, whether behavioural or attitudinal. Religion involves cognitive elements (what we belief), social elements (how we define ourselves) and behavioural elements (what we do) – a three-fold division well understood by Thomas Cranmer as he drafted the Book of Common Prayer "by thought, word and dede".
If you want to research religion seriously, it will involve understanding what people believe, what they say and what they do.
This was recognised in the second stage of the Inductive Business Case developed by the Religious Affiliation Sub-group that was set up by the Census Content Working Group of the Office for National Statistics (we are a long way from Cranmer's elegant prose here) in advance of the 2001 census. The group recognised that there was no "generally agreed map regarding the most economical or efficient number of dimensions [relating to religion]" and that it was important to draw distinctions between belief, affiliation and practice.
That only one of these fed into the 2001 census is understandable (the census was never intended to replicate the 1851 census of religious worship, which sought to make a comprehensive picture of religious attendance). But it has, rather unfortunately, helped foster the idea that religion can be measured by a single figure.
It cannot. Nor, indeed, can it be defined by three: one telling us what people think, one telling us what they say and one telling us what they do. Each of these "dimensions" is itself a complex and ill-defined cluster of factors.
Take belief. Anyone who has given the matter even a moment's thought will realise you cannot simply ask people whether they believe in God or not. Putting aside the inevitable response, "What do you mean by God?" (something that can only be explored properly by qualitative research), belief is not a binary thing, like a light-switch. The interesting question is not so much whether people believe, but how strongly. Thus, when the British Social Attitudes survey measures belief in God they ask people which of six statements "comes closest to expressing what you believe about God," with the statements running from the convinced "I don't believe in God" through various levels of faith and doubt to the equally convinced "I know God really exists and I have no doubts about it".
There are similar complications with what we say about ourselves. Quantitative research relies for the main part on closed questions ("on this scale ... ", "which of these statements … ", etc) which means that when you ask people whether they belong to a religion you have to choose their options for them. This begs questions over which you choose (do you separate out different Christian denominations as they did in Scotland (pdf) but not in England and Wales? (pdf)); what order you put them in (should "None" be the first option as it was in 2001?); should religious questions be compulsory like all others or should they be optional (as they were in 2001)?
And then there is behaviour. Regrettably in Britain we have come to associate religious behaviour with public worship, and although this is probably the most important single behavioural element within the Abrahamic faiths, its forms can change over time. Church attendance, for example, has become much more informal, irregular and dispersed in the post-war period. Moreover, other practices, such as prayer, reading religious texts, giving money and community activity are all critical elements within any serious religious practice. Without them, public worship is a pretty hollow measure.
As if this were not complex enough there are the usual good research practices that need to be observed (keep questions short, options limited, ask the same question, differently phrased, more than once if you can, etc) and the usual problems about interpretation. What, for example, do people mean when they call themselves "Christian"? Having interviewed groups of non-churchgoers who put Christian in the 2001 Census and groups of non-churchgoers who did not, I think the answer is a lot – but not always what one might predict. Like any widely-used social label, "Christian" is painfully malleable, stretching all the way from creedal orthodoxy through moral ambition to the kind of nationalist sentiment that the BNP has recently tried to play on.
It would be easy to read all this as a counsel of despair. It is not. Rather, it is a counsel of caution. Religion is too broad and complex a topic to lend itself to single, easy, incontestable measures. Church attendance does not measure the strength of Christianity in this country, any more than the 2001 census does.
Somewhere between the two, where the different tributaries of our thoughts and words and deeds meet and mix, it possible to research religion seriously and to establish, albeit tentatively, some indicators of how religious the British really are.