Religion in the 21st Century
The secularisation story was largely a Western story. Globally, religious populations are still growing. The data on who believes what, where the world is heading, and why the European pattern is the exception rather than the rule.
(roughly stable for the next 30 years)
(rising; projected to roughly equal Christianity by 2050)
(up from about 16% in 2007 - the fastest growing US religious category)
A note on framing. Religion is one of the topics where the Western press systematically under-covers what is actually happening. The number of religious people in the world is rising, not falling. Western secularisation is a real story but is not the global story. The numbers below come mostly from Pew Research Forum surveys, which are the most carefully constructed of the available sources, supplemented by national censuses and the World Religion Database. The page tries to walk through the actual demographic picture, what is genuinely changing, and what is contested.
The global picture
About 85% of the world's roughly 8 billion people identify with a religious tradition. Christians are the largest single group at about 31%, followed by Muslims at 25%, the religiously unaffiliated at 16%, Hindus at 15%, Buddhists at 7%, folk religions at 5%, and a long tail of smaller traditions. The unaffiliated category - people who do not identify with any religion - is sometimes called "nones" in the demographic literature.
The shape of that picture is changing meaningfully over the next thirty years. Pew Research projections suggest that by 2050:
- Christians and Muslims will be roughly equal in number, each around 30-31% of the world.
- Muslims will be the fastest-growing major group, driven primarily by higher birthrates in Muslim-majority countries.
- The Christian centre of gravity will continue to shift south. About 40% of all Christians will be African by 2060, up from about 25% today. Europe's share of global Christianity will fall further.
- Hindu numbers will keep growing in absolute terms but slowly fall as a global share, mostly tracking Indian demographics.
- The religiously unaffiliated will grow in absolute numbers but fall as a share of the world, because the unaffiliated have lower birth rates than religious populations.
That last point is one of the most consistently misunderstood facts about global religion. Even though the share of "nones" is rising sharply in the US, Europe, and a handful of other developed countries, the global share of religiously unaffiliated people is projected to fall slightly because religious populations elsewhere are growing faster. Western secularisation is real but is being outweighed at the species level by the demographics of the rest of the world.
The Western secular story
The "rise of the nones" in the United States and Europe is real and substantial, even if it does not match the global pattern. The share of US adults who identify as religiously unaffiliated has roughly doubled since 2007, from about 16% to about 30%. In Europe, the share is much higher - ranging from about 20% in Italy to over 70% in the Czech Republic and Estonia. In the United Kingdom, it is over 50%. In Sweden, around 40%. The pattern is consistent: the more developed and economically secure a Western country, the higher the share of unaffiliated.
Most of the decline has come from declining identification with the previously dominant tradition - Christianity in most of these countries - rather than from a rise in identification with non-Christian traditions. People are not switching faiths so much as drifting away from religious affiliation altogether. About 90% of US adults today were raised in a religious tradition; about 30% no longer identify with any. The intergenerational transmission of religious identity has weakened sharply.
But the "nones" category is more complex than it sounds. About 70% of US "nones" still believe in God or some higher power. About 30% report praying weekly. Many describe themselves as "spiritual but not religious." The category captures people who have left organised religion more than people who have rejected the spiritual question entirely. Treating "rise of the nones" as the same as "rise of secular materialism" misses what is actually happening - which is more like a reorganisation of religious life than a wholesale rejection of it.
Where religion is actually growing
The growth of global religion is concentrated in specific regions and traditions:
Christianity in Africa. Sub-Saharan Africa is the most religious major region in the world by every measure. Pew estimates that the number of African Christians will double by 2050, reaching roughly 1.1 billion - more than the combined Christian populations of Europe and the Americas. Pentecostal and charismatic Christianity (which emphasises personal experience, spiritual gifts, and lively worship) is the fastest-growing strand within global Christianity, especially in Africa, Latin America, and Asia. The single largest unreported religious story of the 21st century is probably the African Pentecostal expansion.
Islam globally. The Muslim population is projected to grow from about 2 billion today to about 2.8 billion by 2050. Most of the growth is demographic - higher birthrates in Muslim-majority countries - rather than from conversion. Indonesia, Pakistan, India, Bangladesh, and Nigeria together hold the largest concentrations. Sub-Saharan Africa and South Asia will see most of the absolute growth.
Christianity in Asia. China has had a quiet but substantial Christian growth for decades, with current estimates ranging from 70 to 100 million Christians (the wide range reflects measurement difficulty in a country where religious data is sensitive). South Korea has roughly a third of its population identifying as Christian, much higher than its East Asian neighbours. Vietnam, the Philippines, and parts of Southeast Asia continue to have stable or slowly growing Christian populations.
Hinduism in India and the diaspora. Hindu numbers continue to grow with Indian demographics. The political role of Hinduism in modern Indian politics has intensified considerably under the current ruling party, with implications for the country's religious-minority populations and for India's broader political identity.
Religious nationalism. Across multiple traditions, religion-as-political-identity has gained ground over the last two decades. Hindu nationalism in India, Christian nationalism in parts of Eastern Europe and the United States, Buddhist nationalism in Myanmar and Sri Lanka, and various Islamic political movements have all expanded the political role of religious identity. This is somewhat distinct from religiosity itself - countries can have rising religious nationalism with falling religious participation - and is now one of the most important political-religious phenomena of the period.
How countries actually compare
Religious patterns vary dramatically across countries. The numbers below give a rough sense of religious affiliation and observance, drawn from Pew, the Religious Landscape Study, and various national surveys.
The takeaway: religious patterns differ across countries far more than within most other social categories. Western secular societies are real but they are a minority of the world's population. Most humans live in countries where religious identity is still the dominant cultural fact about most people's lives. The trajectory varies by region and tradition; the simple "religion declines as countries get richer" model is too simple to predict the actual data.
The paths from here
Religion is unusually slow-moving as a social variable. Most of the structural shifts visible today have been underway for decades. The paths below are extensions or variations of trends already in motion.
Continued Western secularisation
The share of religiously unaffiliated continues to grow in the US, Europe, Canada, Australia, and similar countries. By 2050 the unaffiliated may be a plurality or majority in many Western countries. Religious institutions adapt or shrink. Cultural Christianity persists in the background even as practising Christianity declines.
Will it happen? This is the base case for the West. The patterns are well-documented and have not slowed. The deeper question is whether secular cultures can produce the cohesion, meaning, and intergenerational transmission that religious cultures have provided.
Religious revival in parts of the West
Pentecostal Christianity, Hispanic Catholicism in the US, immigrant religious communities, and (in some places) traditionalist Catholic and Orthodox revivals push back against the secular trend. Specific cohorts of younger people return to religious practice for reasons of meaning, community, or family.
Will it happen? Possible in localised forms. Several Western countries already show small reversals among specific cohorts (men over 30 in the US showing renewed religious interest, traditional Catholic communities in France growing, Orthodox Judaism's high birthrate). Whether these add up to a broader reversal is contested.
Continued global religious growth driven by demographics
High birth rates in religious societies (especially Muslim-majority and African Christian) keep global religious population growing. The unaffiliated grow in absolute numbers but shrink as a share of humanity. By 2100, the world is more religious than today, not less.
Will it happen? Highly likely on the demographic side. The deeper question is whether the children of religious parents in developing countries will adopt their parents' religious commitments at the same rate that earlier generations did, or whether they will follow the developed-country pattern of intergenerational secularisation as their countries get richer.
Religious nationalism intensifies
Religion as political identity continues to gain power across multiple traditions. Hindu nationalism, Christian nationalism (in parts of Europe and the US), Buddhist nationalism, various Islamic political movements all become more central to politics in their respective countries. The relationship between religious identity and political identity tightens further.
Will it happen? Already underway. The pattern of the last decade has been a steady intensification of religious nationalism in multiple countries. Whether democratic and pluralist resistances can hold the ground is one of the central political questions of the period.
New religious or spiritual movements
The combination of digital connection, declining institutional trust, and the search for meaning in late-modern societies produces new religious or spiritual movements. Some look like what historians call "great awakenings"; some look like cultic eddies in the larger pool of religiously curious. The category of "spiritual but not religious" remains large and may stabilise into recognisable new traditions.
Will it happen? Some version is virtually certain. New religious movements emerge in every period and most fizzle out; a few persist. Whether the next generation produces traditions of lasting cultural weight or only continued fragmentation is genuinely open.
Religious-secular conflict deepens
In countries where the religious-secular divide is sharp (the US, India, parts of Europe, parts of the Middle East), the political and cultural conflict between religious and non-religious populations intensifies. Education, family, sexuality, gender, and politics all become contested zones where the two sides run on parallel and increasingly non-overlapping cultural tracks.
Will it happen? Already partly happening in several countries. The polarisation feeds on itself: each side's grievances motivate the other side's mobilisation. Whether the trajectory bends toward accommodation or toward sharper separation depends substantially on political choices that have not been made yet.
Migration reshapes religious geography
African and Muslim migration to Europe, Latin American migration to North America, and South Asian migration globally reshape the religious composition of receiving countries. By 2050 the major Western metro areas are substantially more religiously diverse than today, with implications for politics, education, and public life.
Will it happen? Already happening. Demographic momentum makes this a near-certainty for the receiving countries, even with substantial restrictions on migration. The political conversation in the receiving countries about migration is increasingly inseparable from the conversation about religion.
The realistic forecast is, again, a mix. Western secularisation continues but with localised reversals. Global religious population grows in absolute terms because of demography. Religious nationalism intensifies. New movements emerge. The religious-secular divide deepens in some places and softens in others. The simple "religion is declining" framing is wrong at the global level; the simple "religion is rising" framing is wrong for the Western pattern. Both can be true at the same time.
Where serious analysts disagree
Religion is one of the topics where careful analysts using similar data still reach different conclusions, partly because the underlying questions are hard and partly because the analysts themselves often have positions on the questions. Each reading below is held by named scholars whose work is worth engaging directly.
The secularisation thesis was largely wrong
For most of the 20th century, sociologists predicted that religion would fade as societies modernised. The evidence has gone the other way: most of the world remains religious, and the developed-world secular trend is the exception rather than the rule. The secularisation thesis was a Western projection of a Western pattern onto the world, and it should be set aside.
Held by: Peter Berger (who famously revised his earlier secularisation thesis), Rodney Stark, and a substantial fraction of the sociology of religion. Their data on global religious growth supports them. The exception of the developed West is real but is an exception rather than a leading edge.
Existential security drives religious decline
Religion provides meaning, comfort, and community in conditions of uncertainty. When societies become wealthy and stable enough that those needs are met by other means, religious identification declines. The pattern is not coincidence - it is causation. As more of the world reaches developed-country levels of stability, religious identification will fall.
Held by: Pippa Norris and Ronald Inglehart, whose existential security thesis is well-supported across countries. Their projection is for continued slow secular drift as the world gets richer; the demographic offset (religious people having more children) only partially obscures the underlying pattern.
Religious demographics will reshape the future
The intergenerational fertility advantage of religious populations means that the children of more religious parents will reshape the population over generations. Whatever happens to individual religiosity, the share of children raised in religious households will rise globally. The demographic engine is more powerful than the secular conversion engine.
Held by: Eric Kaufmann (Birkbeck, "Shall the Religious Inherit the Earth?"), Nicholas Eberstadt (AEI), and a strand of demographic religious-economy research. The data on fertility differentials is solid; the open question is whether children of religious parents will keep their parents' religion at the same rate as earlier generations did.
Pentecostalism is the most under-covered religious story
The fastest-growing religious movement in the world today is Pentecostal and charismatic Christianity. It is reshaping the religious landscape of Africa, Latin America, parts of Asia, and substantial parts of the United States. The Western press systematically under-covers it because it does not fit Western political categories well. Anyone planning long-term cultural or political analysis without engaging Pentecostalism is missing one of the largest stories of the period.
Held by: Philip Jenkins (Baylor, "The Next Christendom"), Andrew Walls, and a substantial body of mission scholarship. Their data on Pentecostal growth is robust and is consistently confirmed by Pew and other independent surveys.
The "rise of the nones" is shallower than the headlines
Most "nones" still believe in God, still pray, and still consider themselves spiritual. The decline is mostly in religious affiliation rather than in underlying belief or practice. The deeper change is institutional - religious institutions are losing members - more than spiritual. The same human needs that religion has met for millennia are still being met, often through informal or improvised means rather than through traditional churches.
Held by: Christian Smith (Notre Dame), Tara Isabella Burton (writer on contemporary spirituality), and a growing literature on the religious lives of the unaffiliated. Their data on what nones actually believe and practice complicates the simple "secular West" narrative.
None of these readings is fully right or wrong. What can be said from the available evidence: religion globally is more vital than the Western press suggests; the developed-world decline is real but is an exception rather than a leading edge; demographic momentum will keep religious populations growing for decades; Western nones are more spiritually engaged than the label implies; and religious-political identity is intensifying across multiple traditions in ways that will shape the next two decades of global politics.
What this means for you
Religion shows up in everyday life through community, meaning, family identity, ethical judgment, and increasingly through political identity in many countries. A few practical observations that work regardless of one's own religious or non-religious position:
If you are religious
The institutional landscape of your tradition is changing - in most Western countries, traditional institutions are shrinking and newer movements are growing; in many developing countries, the opposite is happening. Engaging with what your tradition is actually doing in your specific community matters more than the headline narrative about religion in your country. The richest religious lives tend to combine local participation with broader global awareness of how the tradition is evolving worldwide.
If you are not religious
The functions religion has historically served (community, meaning, intergenerational ethics, life-cycle rituals, comfort during crisis) are real human needs that do not disappear when affiliation does. Many secular individuals build durable substitutes through close friendships, civic involvement, philosophical practice, secular humanist communities, or simply through deliberate attention to these dimensions of life. The risk for non-religious people is letting the functions atrophy without conscious replacement, which research suggests can have measurable mental-health and relational consequences.
If you are raising children
Children raised with some explicit framework for thinking about meaning, ethics, mortality, and community tend to navigate adolescence and early adulthood better than children raised with no framework at all. The framework can be religious or secular; what matters is that it is articulated and lived. Children who only encounter the metaphysical questions through pop culture and social media are at a disadvantage. This is not an argument for any specific tradition; it is an argument for taking the question seriously rather than leaving the formation to default forces.
If you are thinking globally
Anyone planning long-term work on global politics, business, or culture needs to take religion seriously as a real and growing force in most of the world. Religious literacy - the ability to understand the basic structure, values, and internal diversity of major traditions - is increasingly a basic professional skill, not a specialist hobby. Treating religion as something that "modernised people have moved past" is a 1970s assumption that increasingly clashes with the actual trajectory of the world.
If you live in a religiously polarised country
The religious-secular divide is one of the harder political alignments to navigate well. It tends to map onto deeper questions of identity, family, and meaning, which makes it less amenable to compromise than purely material disagreements. The most useful posture is curious engagement with people across the divide rather than dismissal, ridicule, or avoidance. Most religious-secular polarisation lives in stereotypes that careful conversation generally dissolves; the political commentary is usually more polarised than the underlying populations.
The mechanics behind this
The religion story sits on top of three deeper mechanisms covered elsewhere on this site. If the analysis above depends on ideas you want to understand first, these fundamentals make the conversation more legible:
