Once a religion has become institutionalized or popular, some trends appear that serve to exaggerate statistical measurements of the numbers of adherents (followers) it has. Firstly, people start telling officials that they 'are' a religion for traditional reasons to do with family rather than because it is what they truly believe. Secondly, people start exaggerating how much they are engaged with the religion, i.e. how often they attend religious events such as going to Church on Sunday. Thirdly, the religion itself becomes more diverse and so encompasses a greater number of believers in various things. Fourthly, cultural norms merge with religious norms to produce distinctive practices that are hard to separate into pure categories of religion or culture, meaning that some religionists follow cultural norms without actually believing in the religious side (hence the appearance of atheist Jews, etc). Fifthly and finally, a large number of theologically-illiterate laypeople will confuse any generally religious beliefs with whatever the dominant religion is in their community. So, in Christian countries those who merely believe in God are called Christian whether or not they believe in the complications of Christian theology, but in Muslim countries those same people would call themselves Muslim because they believe in God, whether or not they believe in Islam. Established and traditional religions are over-represented in polls.
People often want to give the 'right' answer on official polls. They want to put the 'right' religion, and so it becomes that entire households and communities state a default religion whether or not they believe in its tenets or even know anything about it. Many know so little about religion that they do not know that a religion is the beliefs. Children, for example, are taught what religion to write down by their parents. Until a child, teenager or young adult understands enough to decide to put down an answer that reflects their beliefs, they will often continue to state their given religion. These implicit religionists distort statistics considerably.
I have personally known many grown adults who consistently put a particular religion (normally 'Church of England'), despite even being atheist. They say that they consider themselves part of that religion because their parents were, or, because they were baptized into it, or maybe simply because they've 'always put that'. This is what happens when a religion has become established in society: even when the basic beliefs in the religion have evaporated its numbers remain inflated as a result of people's habitual form-filling behaviour.
The faster and greater the extent of secularisation of a country, the more prominent this phenomenon will be. It is prominent in Western (European) and developed countries that have generally become very secularized since 1945. last UK census, 72% of the population told pollsters that they were Christian, even though only about half believe in God at all. Clearly, there are many who do not know what 'religion' or 'Christian' means but who continue to describe themselves as Christian. A poll in France shows similar results, "of the 51 per cent who still call themselves Catholics, only half said they believed in God" and the same poll specifically asked why - "many said they described themselves as Catholics because it was a family tradition"1,2.
In addition to these problems with self-identification, often states simply assume that their citizens are sticking to the party line if there is no evidence to the contrary. So, a Government simply presumes to speak for its citizens in saying what religion they are. Some governments do not even collect data about the religious beliefs of their citizens3.
People often think, and say, that they attend services or participate in religious events at about twice the rate that they actually do attend. So, the value obtained when asking people "How often do you go to Church?" gives twice the amount of people who can be counted actually entering Churches for any given event.
Two prominent books on the study of modern religion in developed countries are "Religion in the Modern World: From Cathedrals to Cults" by Steve Bruce (1996)4 and "The C of E: The State It's In" by Monica Furlong (2000)5. They each cite multple studies and detailed statistics, affirming that people attend services about half as often as they say they do6. The Ontario Consultants on Religious Tolerance's essay "How many North Americans attend religious services (and how many lie about going)?" highlights a similar trend in the USA.
“Within most faiths there is a bewildering variety of cultures, languages and traditions. It is important to realize what a vast array of different expressions of faith and experience lie beneath a broad term such as Christianity or Buddhism.”
Even summarizing the main divisions and versions of world religions is said to be impossible8. The main example we will use here is Christianity, because its diversity (both historical and presently) is the widest.
Try reading my exploration of the massive diversity of Christian religions:
One major aspect of Christianity can be said to be the cause of its success: there is a lot of widespread difference in belief across Christian denominations. As perhaps the most fragmented and violent religion in history, Christianity has become broken into countless different denominations and churches, all of which call themselves Christian. Many denominations are intolerant of each other's beliefs. For example any Atlas will tell you that Congo or Angola is dominantly Christian, "and this is true in the sense that many are baptised and go to church. However, people in Congo and Angola constantly talk about ancestors and witches and perform rituals to placate the former and restrain the latter" and this is not something most other Christians ever do9. It can be said that as all these denominations cover such a wide range of beliefs that it is obvious that many people can call themselves a Christian because they're bound to share some beliefs with some denominations. But, merely knowing that they call themselves a Christian gives us very little actual information about their beliefs, as Christianity is such a diverse religion.
“'Christianity' is not a single religion dating from 2,000 years age. A long series of varied different religions, flowing on from one another, have all called themselves "Christian". Rightly so. The beliefs and form have changed so much from time to time that it is best to consider Christianity a series of religions and the word "Christianity" to be an umbrella term for multiple faiths all of which have the same name but different beliefs. Some historical forms of Christianity have made more sense, and some have made less sense, than the Christian mythology that is common today. Modern archaeology has uncovered many of these early forms of Christianity, and no longer can we say that modern-day Christianity in its various forms represents early Christianity. It hardly does. Christianity now is quite varied, but in history the varieties were much more exotic.”
“During the first three Christian centuries, the practices and beliefs found among people who called themselves Christian were so varied that that the differences between Roman Catholics, Primitive Baptists, and Seventh-Day Adventists pale by comparison. Most of these ancient forms of Christianity are unknown to people in the world today. In the second and third centuries there were, of course, Christians who believed in one God. But there were others who insisted that there were two. Some said there were thirty. Others claimed there were 365.”
“The history of early Christianity also includes many difficult conflicts between the competing claims of a still fragile Church with considerable political backing and a host of local cults that somehow deviate from the doctrine. In the case of Christianity, the great difficulty at first was to decide exactly what the doctrine was.”
“The historian, in speaking of Christianity, has to be careful to recognize the very great changes that it has undergone, and the variety of forms that it may assume even at one epoch.”
“In the first few centuries CE there really was no such thing as 'the Church', only competing factions, of which the Literalists were one.”
“[Christians] were divided and split up into factions, each individual desiring to have his own party. [...] Thus separated through their numbers, they confute one another. [... They] are determined in different ways by the various sects.”
And other authors stress the continued variation in Christianity even in the modern world:
“One characteristic of Christianity, deriving from its multiculturalism, is the tremendous variety of "Christianities" around the world. As the religious movement spread, many indigenous people grafted their own religious beliefs and practices onto the basic ideas of the Christian faith. Christian worship often includes pre-Christian religious rituals and takes on the colour and many of the features of the indigenous religions it has replaced.”
In this way all major religions that exist for long period of time (thousands of years) come to be more of an umbrella term for a vast array of beliefs and practices.
It is evident that, for example, mystic Muslims and mystic Christians share much more than do liberal Christians and conservative Christians. The 'wings' of various religions can be so far apart that entire other religions can exist inbetween them. This means that mystics in China may be called Zen Buddhists, but mystics in England may be New Age or Christian. People will identify themselves as a member of a local religion, even if it means stretching the historical boundaries, rather than identify themselves as a member of a distant religion. There is much viscosity preventing people from freely selecting the religion that does historically match their theological beliefs.
All this makes life difficult for the ethnographers who try to measure beliefs and study religions. The more popular a religion is, the more it branches and encompasses wider beliefs, so the less useful are terms such as "Christian". In this way, the most popular religions will have their numbers inflated even if many people actually have beliefs that are best described (unknowingly to the believers) as something else. This can be seen in the very high numbers of Christians in the West who know so little about their own religions that any theologian would call them generic theists or deists rather than specifically Christian or Muslim. Yet as popular religions have diversified and soaked up all of the local religious symbols and practices, wholesale changes in belief and practice will often occur without a wholesale change in religious identification.
Often the history of a people is so intertwined with their religious beliefs that it is difficult to separate their name as a people from the name of their religion. A person can be Jewish because of their family heritage or because of their religious beliefs. So, secular Jews and religious Jews are both called "Jews", and there is no way for an outsider to know if any given Jew is religious or not. Judaism as a religion, including its rites and rituals, is tied up with being a Jew culturally. The self-identity of natural Jews is tied to the religious trappings of Judaism whether or not people continue to believe in the religion itself. In the modern world life is much more compartmentalized so that modern Western religions are distinct from culture, but with older religions this distinction is not part of the world view, and so older religions tend to also be synonymous with cultural practices.
“It is important to understand that a great many Jews have little connection to Judaism as a religion. While many Jews want to maintain their Jewish identity, the majority are secular Jews with little interest in the beliefs and practices of Judaism. For example, less than a third of American Jews are members of one of the religious movement into which Judaism is divided.”
Many of these non-religious Jews still identify themselves as Jews on official forms and questionnaires, so confounding people who attempt, like me, to understand religion and count those who believe.
“There are many Jews who describe themselves as secular but who take part in activities which are, on the face of it, religious. [...] A professor from the Hebrew University in Jerusalem remarked that some people want to take part in secular celebrations of Jewish festivals, while others 'want to get away from religion entirely'”
Pilkington, as part of his introductory chapter on how Judaism is a difficult religion to quantify, shows that the Jewish religious practices are part of a culture of Jewishness that is accepted independently of the beliefs themselves. So, secular Jews still participate in Jewish "religious" festivals for cultural reasons despite not having Jewish beliefs. This makes it seem that there are more Jewish believers than there are. It is hard to count atheists worldwide, when Jewish and Christian atheists, for example, continue to call themselves Jews and Christians for cultural and traditional reasons.
The way Westerners classified Hinduism as a 'religion' confused Hindus for a very long time as they had such a massive variety of practices and beliefs, all tied up with their culture and with no central beliefs or defining organisations. It is only with multiculturalism that a religion is forced to coalesce out of a rich culture.
Cultural religious affiliation causes exaggeration of the amount of believers a religion has. The ritualistic, ceremonial and dogmatic trappings of religion are accepted independently of belief, so the total numbers of believers is probably always exaggerated whenever a community has an assumed cultural religion. Often members of such a community will not even call themselves "religious", because it is the norm and such a distinction is unnecessary.
We have already taken note that 72% of the British public identify themselves as Christian, yet less than half believe in god. The same situation exists in the USA. Of the 5% of Americans who said they do not believe in God in 2007, only a quarter labelled themselves as atheist. 3 in 20 of American who tell pollsters that they don't believe in God also still call themselves Christian, another 1 in 20 still call themselves Jewish18. A loss of belief has not resulted in people correctly changing their religious self-identification. This hides the rate of secularisation from official pollsters by at least one third in the UK. In other words, at least one third of those who say they are Christian actually aren't. The true number of Christians and theists in ageing Western countries is much less than official statistics show, perhaps as low as one quarter or one fifth. The main bulk of secularisation exists first in generations of people who no longer know what it is to be religious.
“Children who do not come from churchgoing homes - as I did not - now grow up largely ignorant of Christian ideas in a way unimaginable half a century ago. [...] The comments about religion by journalists in the press and on television [...] suggest that even the basic Christian ideas are no longer understood by university-educated people, still less by others. Indeed even churchgoers can reveal an ignorance of the main elements of Christian belief.”
"Religion in the United Kingdom: Diversity, Trends and Decline" by Vexen Crabtree (2020) is a compilation of many statistics on religion in Britain, a country that serves as one of the most striking examples of a populace who have forgotten religion in all but name. Noting that 71.1% of the population of England and Wales said they were Christian:
“Large-scale studies have shown that many of them don´t accept some - or sometimes any - of the basic tenets of the faith they purport to belong to. The BBC´s survey "Soul of Britain" found a huge proportion of nominal Christians who didn´t believe in the virgin birth, the resurrection or the miracles. They didn´t believe that Jesus was the Son of God and, indeed, a good number of them didn´t even believe in a personal God of any kind.”
Theism is the belief in god(s), polytheism the belief in multiple gods and monotheism (like Judaism, Christianity and Islam) the belief in a single god.
Because Christianity is the dominant religion in the UK, most people who believe in a god here think that they are Christian. As a result of secularisation they do not know, understand, or care, what the differences are between the hundreds of god-believing religions in the world, generally because they don't know about them, nor do they want to know. In other words, most god-believers are theists and should not rightly be counted as Christians. This must also happen in other countries - there must be many Muslims who believe in god (who are 'theists') but who don't really care for the specifics of Islam, but, do not know what else to call themselves. They will still be caught up in all the cultural-religious practices centering on Mosques because they simply know no better.
The established religion takes monopoly on divinity, so that those with almost any basic beliefs at all automatically consider themselves a member of that religion. This is because that frequently they do not actually know the particulars of the beliefs or texts of the common religion. If asked more complex questions about their stated religion, they would be shown to have very few other actual beliefs in common with the religion they identify as.
Dominant local religions therefore soak up a great mass of general theists and general believers, who are only members of the religion because they are limited by lack of knowledge or freedom to call themselves anything else. In fact, it might only take a small percent of highly motivated activists to convert large communities of largely placid followers. Should these grassroots followers really be counted as 'believers' of the religions, which often have theological depths and complicated beliefs that are far from what the masses actually believe? Questions like these are discussed in "Cultural Religion Versus Scholarly Religion" by Vexen Crabtree (2013).
Even in liberal Western countries some of those who do not belong to certain religions hide their religion. Especially members of non-world religions such as Paganism, Wicca, Satanism, etc, those which have historically been oppressed by Christian organizations. For example, at a London Satanists gathering I polled all the members present about what they had put on the 2001 April National Census, and half of them said they had put "no religion". This is a significant under-representation.
"A census is inevitably based on self-definition, and those who identify as Buddhists are likely to include people who live in Buddhist centres or work full-time for a Buddhist organisation or have given up their ordinary lives to become monks or nuns, as well as people who once attended a Buddhist group for a couple of weeks or have learned what they know of Buddhism from books"20. In other words, people tend to say on the census and on other impersonal, official forms that they are "Buddhist" simply because they have an interest in Buddhism and/or, they have attended some Buddhist evenings/days, which are actually only a watered-down, disguised form of New Age religious selectivism. Of the 144,453 who put down "Buddhist" on the 2001 Census, I suspect 100,000 are Buddhism-fans, not Buddhists.”
This is a continuation of the hidden theme of secularisation: People no longer accept religions, but rather they nibble at bits and pieces of religious thought and practice. As this is as far as religion goes in the secular world, those who partake of these little bits immediately self-classify as an adherent even though they are far from being so.
Great numbers of people tend to identify themselves with the locally dominant religion despite what their actual beliefs are, and despite mass secularisation in the West. General god-believers (theists) will nearly always identify themselves as Christians or Muslims despite sharing no other beliefs with those complex religions, and even atheists continue to fill in the 'religion' field on official polls as if they still believed in the religions of their ancestors. People guess that they attend church twice as regularly as they actually do. Official polls of dominant religions return numbers far in excess of those who actually believe or follow the religion. These effects are more pronounced the bigger the religion is, and the longer that it has been established for. Advanced secularism (such as seen in the UK or Israel) can be masked by these form-filling-specific behavioural quirks.
Opinion polls based asking questions about specific beliefs return a truer picture than do sweeping questions asking people to state a religion - but there are not many national census questionnaires that have the room for such detail, therefore formal adherency counts of once-popular mainstream religions remain high even while actual belief dwindles.