Religion in the 21st Century
Religious populations are still growing in number, mostly through births, but the share of the world with no religion rose between 2010 and 2020. The data on who believes what, where the trends point, and whether Europe's secular pattern is an exception or a preview.
(Pew, 2025; down from 77% in 2010)
(24% in 2010; Christians 29%, down from 31%)
(Pew; 16% in 2007, roughly flat since about 2020)
A note on framing. Western decline is only part of the religion story. The numbers below come mostly from Pew Research Center, whose global estimates draw on more than 2,700 censuses and surveys, supplemented by national data and the World Religion Database. The page walks through the demographic picture, what is changing, and what is contested.
The global picture
In 2020, the latest year Pew has estimated, about 76% of the world's 7.9 billion people identified with a religion. Christians were the largest single group at about 29%, followed by Muslims at 26%, the religiously unaffiliated at 24%, Hindus at 15%, Buddhists at 4%, 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. Pew's estimate for them is far above the 16% it published in 2015, mainly because it now counts most people in China as unaffiliated.
Pew's global projections, made in 2015 from 2010 data, suggested 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 center of gravity will continue to shift south. About 40% of all Christians will live in sub-Saharan Africa, up from 25% in 2010 and 31% in 2020. 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 projection has not held so far. From 2010 to 2020 the unaffiliated share of the world rose from 23.3% to 24.2%, because switching out of religion, mostly by people raised as Christians, outweighed the birth gap (Pew, 2025). Whether switching keeps outpacing births is now the open question, since the unaffiliated are older on average and have fewer children.
The Western secular story
The "rise of the nones" in the United States and Europe is real and substantial. The share of US adults who identify as religiously unaffiliated rose from 16% in 2007 to 29% in 2023-24. Europe varies widely, from under 1% unaffiliated in Romania and 13% in Italy to 54% in the Netherlands and 73% in the Czech Republic (Pew, 2020). In England and Wales, 37% reported no religion in the 2021 census; in Scotland's 2022 census, 51% did. Wealth and security track the pattern only loosely, as the Czech Republic and neighboring Poland (9%) show.
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 80% of US adults were raised Christian, but 22% of all adults no longer identify as Christian (Pew, 2023-24). The intergenerational transmission of religious identity has weakened sharply.
But the "nones" category is more complex than it sounds. Most US "nones" still believe in God or some other higher power; only 29% reject the idea. About half say they are spiritual or that spirituality is very important to them, though 90% seldom or never attend services (Pew, 2024). The category captures people who have left organized religion more than people who have rejected the spiritual question entirely. Some scholars read this as a reorganization of religious life rather than a wholesale rejection of it; others see a way station on the road out.
The US trend has also stopped moving. Pew's Religious Landscape Study, fielded across 2023 and 2024 among nearly 37,000 adults, found 62% of US adults Christian, down from 78% in 2007; Pew's annual surveys have put that share at 60-64% since 2019. The unaffiliated share stopped growing at the same time, and prayer and attendance have held steady since about 2020. A December 2025 Pew review found no clear evidence of a nationwide revival, and Pew's 2026 survey put the unaffiliated at 28%. Gallup's measure edged up: 24% had no religious preference in 2025, a record.
It is worth being careful about what that does and does not mean, because on Pew's data both readings on offer are wrong. This is not a revival: nothing has reversed, and no measure has recovered ground. Young American men are now about as religious as young women, but because women's religiosity fell faster, not because men's rose. Nor is the plateau necessarily a floor. The age gradient underneath is steep - 46% of 18-to-24-year-olds identify as Christian against 80% of those 74 and older - even though adults born from 2000 to 2006 are as religious as those born in the 1990s. Arithmetic alone will push the totals down again as older cohorts are replaced, unless today's young adults become more religious as they age or a more religious generation follows them.
Where religion is growing
The growth of global religion is concentrated in specific regions and traditions:
Christianity in Africa. Sub-Saharan Africa is among the most religious regions in the world on almost every measure. In 2020 it overtook Europe as home to the largest share of the world's Christians (31%, against 22%), and Pew's 2015 projections have its Christian population passing 1 billion by 2050 - more than Europe and North America combined. Scholars of world Christianity such as Philip Jenkins see Pentecostal and charismatic Christianity (which emphasizes personal experience, spiritual gifts, and lively worship) as the fastest-growing strand of the faith, especially in Africa, Latin America, and Asia.
Islam globally. The Muslim population grew by 347 million between 2010 and 2020, more than all other religions combined, to about 2 billion; Pew's 2015 projections put it at about 2.8 billion by 2050. Most of the growth is demographic - young populations and 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's Christian population grew fast for decades - to 38 million Protestants by 2018 on official figures - but surveys suggest the growth has stalled since 2010. Estimates range from about 20 million self-identified adults to more than 100 million; 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 (32% in 2020, on Pew's estimate), much higher than its East Asian neighbors. 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.
How countries compare
Religious patterns vary dramatically across countries. The numbers below give a rough sense of religious affiliation and observance, drawn from Pew's estimates for 2020, its Religious Landscape Study, national censuses, and other surveys.
The takeaway: 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 "religion declines as countries get richer" model captures a real tendency but misses many cases.
The paths from here
Dated September 2026, with the world's unaffiliated share rising in 2010-2020 and US religious identity flat on Pew's measures since about 2020. Religion is unusually slow-moving as a social variable. Most of the shifts visible today have been underway for decades. The paths below are extensions or variations of trends already in motion.
Continued Western secularization
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 practicing Christianity declines.
Will it happen? This remains the base case for most of the West: from 2010 to 2020 the unaffiliated share rose in 40 of 46 countries and territories in Europe, North America, and Australasia (Pew). The United States has paused since about 2020. An open question is how well secular institutions can supply the cohesion, meaning, and intergenerational transmission that religious ones 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 localized forms; claims of a broad youth revival have not held up. In Britain, the Bible Society withdrew its 2025 "Quiet Revival" report in March 2026 after YouGov said the poll behind it was flawed by fraudulent responses, and the random-sample British Social Attitudes survey shows weekly churchgoing among under-35s flat at 3-5% since 2017. In the US, Pew finds stability since 2020, not growth. Local rises are real: adult baptisms in France more than tripled in ten years, to 13,234 at Easter 2026, and Orthodox Jewish communities grow through high birthrates. 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? Likely for numbers, less certain for shares, which moved the other way in 2010-2020 as switching outweighed the birth gap. The deeper question is whether the children of religious parents in developing countries will keep their parents' religious commitments as earlier generations did. They may instead follow the developed-country pattern of intergenerational secularization 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. Pew's related index of government restrictions on religion was in 2023 at its highest median level since tracking began in 2007. How far the trend goes, and how pluralist institutions respond, 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 stabilize into recognizable 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 open.
Western secularization continues, paused in the United States and with local exceptions. The number of religious people keeps growing because of demography, while their share of the world edges down. Religious nationalism intensifies. New movements emerge. The religious-secular divide deepens in some places and softens in others. Neither "religion is declining" nor "religion is rising" fits the whole picture: each is true of some measures and places.
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 secularization thesis was largely wrong
For most of the 20th century, sociologists predicted that religion would fade as societies modernized. 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 secularization thesis was a Western projection of a Western pattern onto the world, and it should be set aside.
Held by: the late Peter Berger (who famously revised his earlier secularization thesis), Rodney Stark, and a substantial fraction of the sociology of religion. Their strongest evidence is the continued growth in the number of religious people worldwide. Critics reply that the growth comes mainly from births, and that from 2010 to 2020 the share of the world with no religion rose (Pew).
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 draws on cross-national survey data. 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. Supporters point to the United States, where the share calling religion important in daily life fell from 66% in 2015 to 49% in 2024 (Gallup). Critics point to cases wealth does not explain, such as the gulf between the Czech Republic and Poland.
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 (Buckingham, "Shall the Religious Inherit the Earth?"), Nicholas Eberstadt (American Enterprise Institute), 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"), the late Andrew Walls, and a substantial body of mission scholarship. Critics note that most Pentecostal counts rest on churches' own figures rather than censuses or surveys (Pew), and that evangelical growth has slowed in places such as Brazil.
The "rise of the nones" is shallower than the headlines
Most "nones" still believe in God or a higher power, and about half 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. Critics reply that commitment is falling too: Americans calling religion very important in their lives fell from 58% in 2012 to 47% in 2025 (Gallup).
What the evidence supports so far: the number of religious people is still growing, mostly through births, while their share of the world edged down between 2010 and 2020. The developed-world decline is real; whether it is an exception or a leading edge is what the first two readings dispute. Western nones are more spiritually engaged than the label implies, though commitment is falling too. 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.
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 may navigate adolescence and early adulthood better. A 2018 study that followed several thousand young Americans linked religious upbringing with greater life satisfaction and less drug use; secular frameworks have been studied less. The framework can be religious or secular; the point is that it is articulated and lived. Children who only encounter the metaphysical questions through pop culture and social media may be 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 "modernized people have moved past" misreads a world in which three-quarters of people still identify with a religion and their number keeps growing.
If you live in a religiously polarized 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 polarization lives in stereotypes that careful conversation generally dissolves; the political commentary is usually more polarized 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:
