Is religion dying? Secularization theory against the 2020s data

Is religion dying? In rich countries, fewer people pray, attend services or call themselves Christian than a generation ago. Worldwide, three in four people still have a religion, and the Catholic Church is growing. This post tests secularization theory, the claim that modernisation erodes religion, and its main rivals against the best 2020s data: Pew's 2025 global estimates, the US Religious Landscape Study, the Catholic Church's own statistics, Pew's survey of Orthodox Christianity, and the UK "Quiet Revival" survey, whose headline figures collapsed in 2026.

Part 8 of How did religion develop?. Previous: Where did religion come from?. This is the last part. Back to the series introduction.

The theories

The classic theory is covered by standard works that the notes cite from their bibliographic records, so they are paraphrased here:

Secularization. Max Weber described modernity as a disenchantment of the world. Peter Berger's The Sacred Canopy (1967) argued that pluralism dissolves the shared plausibility that religion needs. Steve Bruce's God is Dead (2002) defends the paradigm for the West, with decline driven by each generation being less religious than the last.
Supply-side. Rodney Stark and Laurence Iannaccone (1994) argued that demand for religion is stable. State monopolies make churches lazy, and competition raises participation, so Europe's decline reflects its religious markets, not modernity as such.
Desecularization. In 1999 Berger recanted much of his earlier view, arguing that most of the world is as religious as ever, with Western Europe and a global intellectual elite as the exceptions.
Existential security. Pippa Norris and Ronald Inglehart (2004) argued that religiosity falls as human security rises, but that the world as a whole grows more religious because poorer, more religious societies have more children.
Reframings. José Casanova (1994) split secularization into three claims: differentiation of spheres, which he accepts; decline, which he says is not universal; and privatisation, which he rejects. The Catholic philosopher Charles Taylor (A Secular Age, 2007) rejects stories of religion simply being subtracted, and describes a shift to a world where belief in God is one option among others.

(All bibliographic.)

The global picture: Pew 2025

Pew's 2025 report on 2010–2020 gives the best current global estimates (Pew 2025):

Christians: 2.3 billion in 2020, up 122 million, but their share fell 1.8 points to 28.8%.
Muslims: up 347 million, more than all other religions combined. Their share rose 1.8 points to 25.6%.
Religiously unaffiliated: 1.9 billion, up 270 million, from 23.3% to 24.2% of the world.
Anyone with a religion: 75.8% of the world in 2020, down from 76.7% in 2010.
Switching: among adults aged 18–54, about 3.2 people left religion for every one who joined, and Christians had about 3.1 leavers per joiner. Muslim growth came mainly from a young population and high fertility.
The centre of gravity has moved. 30.7% of the world's Christians lived in sub-Saharan Africa, against 22.3% in Europe. Christians fell below half the population in the UK (49%), Australia (47%), France (46%) and Uruguay (44%).

Pew's 2015 projections expected the unaffiliated share to fall by 2050. Pew now says that report's 2010 baseline has been revised, partly because China was re-measured, and that new projections past 2020 are not yet available (Pew 2015 note).

The United States: decline, then a plateau

Voas and Chaves (2016) argued that the United States should no longer be treated as the great counterexample to secularization. American religiosity has been declining for decades through the same generational replacement seen elsewhere in the West (Chaves & Voas 2016). Pew's Religious Landscape Study of 36,908 adults (2023–24) shows Christians at 78% in 2007, 71% in 2014 and 62% in 2023–24, and the unaffiliated at 16%, 23% and 29%. Since 2019 the Christian share has been "relatively stable, hovering between 60% and 64%" (Pew 2025). The age gap is large. Among 18–24-year-olds 46% are Christian, against 80% of those 74 and over. But people born in the 2000s are about as likely to identify as Christian as those born in the 1990s. That is a cohort plateau, not a revival.

The Catholic Church's own numbers

According to the Fides summary of the Church's Statistical Yearbook, there were 1,405,454,000 Catholics in mid-2023, 17.8% of humanity, up almost 16 million in a year (Fides 2025). Of the increase, 8.3 million were in Africa and 5.7 million in the Americas, and only 0.74 million in Europe. Priests numbered 406,996, down 734. Major seminarians fell from 108,481 to 106,495. Permanent deacons rose to 51,433. Dividing the figures gives roughly 3,450 Catholics per priest, the notes' own arithmetic, and the ratio keeps rising.

In the US, Catholic identity has held at 19–21% in all but one of 11 Pew surveys since 2014. CARA's modelled estimate of weekly Mass attendance averaged 24% from May 2023 to early 2025, back to the pre-pandemic 24.4%. It combines surveys with search data, so it is a model, not a headcount (CNA).

Orthodox Christianity: identity and practice

Pew counted nearly 260 million Orthodox Christians in 2017, more than double the number a century earlier. Over the same period they fell from about 20% of the world's Christians to 12%. The contrasts within Orthodoxy are stark. Weekly attendance was 6% in Russia against 78% in Ethiopia. Religion was "very important" to 15% of Russian Orthodox and to nearly all Ethiopian Orthodox (Pew 2017). Russia's post-Soviet revival is mostly one of identity, not practice. In October 2018 the Russian Orthodox Church broke communion with the Ecumenical Patriarchate over Ukrainian autocephaly. That is the most serious split in Orthodoxy in centuries, and it remains unhealed (AsiaNews).

In the US, reports of a wave of converts to Orthodoxy, especially young men, rest mostly on parish accounts and studies by Orthodox institutions. The strongest hard figure is Pew's finding, as cited by the BBC, that US Orthodox Christians are now 64% male, up from 46% in 2007 (Baylor Religion Watch). Orthodoxy is under 1% of US adults, so that subsample is small, and a 2008 survey already found that 29% of Greek Orthodox and 51% of OCA members were adult converts (Christian Century). The wave is plausible but weakly measured.

The "Quiet Revival" and its problems

In April 2025 the Bible Society published The Quiet Revival, based on YouGov fieldwork. It reported that the share of adults in England and Wales who identify as Christian and attend church at least monthly had risen from 8% in 2018 to 12% in 2024, and among 18–24-year-olds from 4% to 16%. Critics warned early that YouGov's opt-in online panel was vulnerable to bogus respondents, that the sample's Christian identity (33%) was well below the 2021 Census (46%), and that the results conflicted with probability surveys and with denominational attendance counts (Christian Today).

In March 2026, YouGov's re-analysis found "a number of respondents who we can now identify as fraudulent". Its chief executive, Stephan Shakespeare, said YouGov "takes full responsibility" and apologised. YouGov said the Bible Society had reported the data accurately, and the survey is being rerun. The Bible Society's chief executive said he was deeply disappointed but pointed to other probability surveys showing greater engagement among young adults (Christian Post). Until the rerun is published, the headline figures should be treated as discredited. The wider lesson applies on both sides of the Atlantic. Stories of young men returning to church rest partly on opt-in online samples, the method most exposed to fraudulent respondents.

Through the lenses

Sociology

The 2010–2020 pattern looks like Norris and Inglehart's prediction: switching runs towards no religion, while the religious share holds up through fertility in less secure, more religious populations. It is harder to square with a pure supply-side model, which predicts no net drift. Berger's recantation stands as a claim about global religiosity by headcount, not as evidence against secularization in rich democracies. Berger himself made the exception for Europe. Voas and Chaves point to cohort replacement as the engine of decline, with plateaus between cohorts.

Economic history

The Reformation's long legacy has been tested too. Becker and Woessmann (2009), using 452 Prussian counties, found that Protestants' higher literacy, from Bible reading, accounts for most of their economic advantage, rather than Weber's work ethic (RePEc).

Demography

Christianity is shifting south rather than simply shrinking. Pentecostal and charismatic Christians are counted in the hundreds of millions by the World Christian Database, but totals swing by hundreds of millions depending on definitions (Lifeway summary), so any figure should be cited with its edition.

Catholic theology

The Church's statistics are themselves a lens. They show a global Church that is growing in Africa and Asia, with falling vocations in the West and seminary numbers falling year after year. Taylor's account gives Catholics a non-triumphalist reading of the West: belief has become one option among others, which changes the conditions of faith without deciding its truth. The CCC §28 claim that humans are religious beings is consistent with global headcounts. Whether it is consistent with the cohort-by-cohort decline in rich countries is the hard question. A theological answer would distinguish a universal religious capacity from its institutional expression, but that is a claim the data cannot test.

Orthodox theology

Schmemann defined secularism, as one scholarly article reports, as above all a negation of worship (bibliographic, at summary level). Pew's numbers make that reading concrete: in Russia, identity without practice; in Ethiopia, practice at levels found almost nowhere in the West. Casanova's distinction fits Russia well, since public religion can grow while private practice stays low. The 2018 schism shows that Orthodoxy's sharpest modern crisis is ecclesial and political, not a matter of secular decline.

What we can say with confidence

Worldwide, 2010–2020 saw net switching away from religion, while the religious share stayed high through fertility. In 2020, 75.8% of people had a religion.
In the US, Christian decline paused after 2019 at about 60–64%.
The Catholic Church grew to about 1.405 billion in 2023, mostly in Africa, while priests and seminarians declined.
Orthodox practice varies enormously, from 6% weekly attendance in Russia to 78% in Ethiopia.
The UK "Quiet Revival" headline figures are discredited pending YouGov's rerun.

What remains open

Whether the US plateau holds or is a pause between cohorts.
What the post-2020 global projections will show; Pew has not yet published them.
How large the US Orthodox convert wave really is.
Whether secularization in rich countries is a general law of modernity or one regional path among several.

Sources

Becker, S. O. & Woessmann, L. (2009). QJE 124(2):531–596. RePEc
Berger, P. L. (1967; ed. 1999); Bruce, S. (2002); Casanova, J. (1994); Norris, P. & Inglehart, R. (2004); Stark, R. & Iannaccone, L. (1994); Taylor, C. (2007); Weber, M. (1917/1919) (all bibliographic).
CARA Mass attendance estimates, via CNA (2025)
Chaves, M. & Voas, D. (2016). American Journal of Sociology 121(5):1517–1556. Duke; Voas on LSE USAPP
Christian Post (2026). YouGov retracts Bible Society's Quiet Revival study. Link
Christian Today. The Quiet Non-Revival. Link
Fides (2025). Catholic Church Statistics 2025. Agenzia Fides
Krindatch 2008 convert survey, via Christian Century
Lifeway Research, summary of Gordon-Conwell status report. Link
Moscow–Constantinople break (2018). AsiaNews
Pew Research Center (2015). Religious projections 2010–2050. Pew
Pew Research Center (2017). Orthodox Christianity in the 21st Century. Pew
Pew Research Center (2025). Decline of Christianity in the US has slowed. Pew
Pew Research Center (2025). How the global religious landscape changed from 2010 to 2020. Pew
Schmemann on secularism, via RESS 2023. PDF
US Orthodox converts, Pew via BBC. Baylor Religion Watch

The notes behind this post: 08_modern_secularization.md.

Part 8 of How did religion develop?. Previous: Where did religion come from?. Start again from the series introduction, or from Part 1: Why are humans religious?

Produced with AI assistance (Claude) from the cited notes in the religion-origins project.