“Importance of religion has declined dramatically across the world”

Sociologists of religion present a new edition of one of the most comprehensive empirical studies of religious trends across the world – Detlef Pollack: the importance of religion has declined dramatically across the world, even in former religious strongholds – “Even predominantly Muslim countries such as Iran and Turkey are not spared from the decline in religion” – Updated and expanded new edition of the standard work “Religion and Modernity”

Press release from 1 July 2025

According to new studies in the sociology of religion, the importance of religion and religious institutions has declined dramatically across the world in recent years. “Increasing secularization, i.e. the decline of religious ties, affects not only regions of Western Europe, where these trends have long been observed, but also former religious strongholds such as Poland and the US, as well as South Korea and Japan. This also applies to predominantly Muslim countries in North Africa, Turkey and Iran”, says sociologist of religion Prof. Dr. Detlef Pollack from the Cluster of Excellence “Religion and Politics” at the University of Münster. He and his colleague Dr. Gergely Rosta have published a greatly expanded and revised new edition of their standard work “Religion and Modernity: An International Comparison” with Campus Verlag. According to the authors, the third edition differs greatly from the first: “The sociology of religion has observed for decades a decline in ties to religion and the church in Western Europe, including West Germany. However, the dramatic declines across the world in recent years came as a surprise even to a secularization theorist like me – it is these trends that the new data in the book show.”

The proportion of people without religious ties in the US, for example, remained in the single figures throughout the 20th century, but has since risen to just under a third, Pollack explains. “In Poland, which had enjoyed remarkable religious stability, weekly churchgoing fell by ten percentage points between 2015 and 2021 alone”. Among the predominantly Muslim countries, it is secularization in Iran that is particularly noticeable: “Contrary to official figures that claim that more than 99% of Iranians identify as Muslim, an online survey suggests that that figure is in fact only about 40%. About 22% say that they do not belong to any religion, and about 9% are atheists”. Although there has been an increase over the past 20 years in the attention that society pays to religion and in the number of political conflicts with a religious undercurrent, we cannot ignore the decline in religious ties in many regions of the world. Contrary to what theologians may claim, the validity of secularization theory, which argues that processes of modernization are linked to the decline in the importance of religion and churches, is beyond dispute.

“For many, belief in God or an afterlife is no longer plausible”

The study explains the decline in the importance of religion by pointing to factors such as growing prosperity, democratization, the expansion of the welfare state, individualization, and cultural pluralization. “The conditions under which religious belief systems have to prove themselves have changed so fundamentally that belief in an afterlife, in God, in the efficacy of religious rituals, and in the salutary power of religious institutions – this is no longer plausible for many people”, according to Pollack. “Drawing on these categories in the sociology of religion, we can say that secularization theory has great explanatory power when it comes to analyzing religious change in modern societies”.

There has recently been a reignition of the debate on secularization theory: “What prompted us in the third edition of the book to thoroughly revise our arguments”, says Pollack, “were new data – and, not least, the findings, disputed by some German theologians, of the 6th church membership survey conducted by the Evangelical Church in Germany (EKD)”. “Whereas in the first two editions we cautiously sought evidence for secularization theory, this now constitutes the very foundation of our argument”. At the heart of the latest debate are questions about how religion is understood. According to Pollack, some critics of secularization theory draw on the notion of “lived religion” to argue that the focus should be on the individual’s self-image, i.e. what is personally important to them. “This vague concept of religion has given rise among some German theologians to a refusal to acknowledge empirical findings that clearly show a decline in the importance of religion and religious ties across the world”.

Broad database – standard work in the sociology of religion

Now regarded as a standard work in the sociology of religion, “Religion and Modernity: An International Comparison” is based on a wealth of data from large parts of Western and Eastern Europe, South and North America, and Asia, and identifies the political, national and social factors that influence religion. Pollack and Rosta conduct case studies for Italy, the Netherlands, East and West Germany, Poland, Russia, the US, South Korea, and Brazil, and compare these countries to draw general conclusions. They paint a detailed panorama of religious change in different societies. Analyses of the present are complemented by historical perspectives (see key findings below).

The study includes a large number of representative datasets from different periods: the World Values Survey (WVS), the International Social Survey Programme (ISSP), the General Population Survey of the Social Sciences (ALLBUS), the Bertelsmann Foundation’s Religion Monitor, the General Social Survey (GSS), the global findings of the Pew Research Center, surveys conducted by the researchers themselves among Muslims living in Germany, and church and government statistics. Detlef Pollack: “The study refrains from developing a universal theory that integrates all factors of religious change, but instead combines different theoretical perspectives”. (fbu/vvm)

Literature: Detlef Pollack and Gergely Rosta: Religion in der Moderne. Ein internationaler Vergleich (“Religion and Modernity”, Volume 1), 3rd updated and expanded edition, Frankfurt am Main/New York: Campus Verlag 2025.

1) When religious identities are linked to political, economic, or national interests, this often helps strengthen religion and the church. The study illustrates this correlation using the example of Russia, where identification with Orthodox Christianity has risen rapidly among large sections of the population in recent decades, accompanied by an equally marked increase in national pride. After the collapse of the Soviet Union, the Russian Orthodox Church became the new marker of identity, with church and state forming a close alliance. Religiosity should therefore be understood as an expression of cultural identity rather than a form of internalized faith, as Detlef Pollack has recently said with regard to the Ukraine war. This also explains the appeal of Pentecostal churches in Latin America and Protestant churches in South Korea, which promise their members greater prosperity and social advancement if they live a disciplined life.

2) Religious ties often weaken again once the political, economic, or national goals pursued through religious means have been achieved. According to the study, higher levels of prosperity or the expansion of social and educational systems often mean that people no longer need to use church channels, since other avenues are now open for political participation, professional training, and social support. Religious identity loses some of the multifunctionality once crucial to its maintenance and must rely increasingly on purely religious motives. Sociologists refer to this as functional differentiation, which they see as a key feature of modern societies: social subsystems such as religion, politics, law, and economics diverge and gain functional autonomy, this reducing the opportunities for religion and the church to influence non-religious spheres and to shape social life. The study argues that, even if differentiation does not lead automatically to a decline in the importance of religion, such an effect is very likely.

3) If political or other non-religious interests coincide with religious interests, then non-religious interests may absorb the religious. As studies in some countries show, the link between religion and political interests can lead to increasing dechurchification. In the US, for example, many people who had already distanced themselves from religion have recently abandoned their religious ties altogether as a result of the alliance between evangelicals and conservative political positions, with moderate Protestant mainline churches being particularly affected by a decline in membership. These are often what sociologists term processes of absorption: a religion whose relevance is tied to its non-religious benefits risks being compared and replaced, and having the goods of salvation that it offers devalued.

4) The dwindling belief in a personal God is a sign of advancing secularization. There is a growing shift across the world away from belief in a personal God, one who can intervene in people’s lives and whom believers must justify themselves to. In most Western European countries, the majority of believers have turned away from belief in a personal God as proclaimed in the Bible, and now believe only in a higher power that cannot be experienced directly. The study interprets this “liquefaction of transcendence” not only as a change in the content of religiosity, but also as an expression of advancing secularization. The reasons behind these tendencies include people’s growing scepticism towards all-encompassing worldviews and ideologies. The surveys in the study show that a diversity of spiritual options does not help strengthen faith.

5) The more people value self-determination, enjoyment of life, and self-fulfilment, the more distant they are from the churches. Even though surveys show that a majority of people in Germany believe that they can be religious without the church, this can only be proven statistically for a minority. The surveys show that only a few actually live their Christian faith outside church institutions and communities. How important social integration is for faith can also be seen in the fact that highly individual forms of esoteric spirituality outside the church and Christianity often fluctuate wildly. Sociologists use the thesis of coupling to denote this process: religious ideas gain persuasive power when individuals share them with others, when they participate in church life, and when their faith is supported communicatively and institutionally.

6) The more opportunities there are for self-realization in work and leisure, the more attention shifts from religious to secular practices. With their wide range of cultural, entertainment, and leisure activities, modern societies offer a range of alternatives to religious lifestyles. The study refers to this as “distraction”: when there is a wide range of non-religious activities on offer, then attention shifts from religion to other areas of life such as work, family, friendship, entertainment, and consumerism. The weakening of religious ties is often not the result of a conscious decision between religious and non-religious options, but rather a gradual process whereby people re-prioritize their values.

7) The differentiation of society generally has a negative effect on religiosity, but can also strengthen religious plurality in specific areas. As has been observed in Western Europe since the 1960s, religiosity generally declines as society becomes more differentiated into individual areas such as politics, law, religion, and economics. Nonetheless, the study also identifies certain countervailing trends. For example, in functionally differentiated societies that separate church and state, there can emerge new freedoms for religious communities. Thus, in Turkey, the Alevis are not respected as a separate religious group and are politically oppressed, whereas in Germany they are a recognized body under public law.

8) External religious coercion through institutional rules and community expectations stops people internalizing religious ideas and practices. According to the study, while faith benefits from a communal and institutional framework, if this is so strong that individuals have little personal freedom, then the effect is reversed and the intrinsic motives for faith are weakened. The legacy of the state church plays a major role in Western Europe, for example. Unlike in the US, where church and state have been institutionally separate for more than 200 years, the church in Germany and other Western European societies is often seen as an authoritarian institution of power, which leads to widespread scepticism towards the church.

9) Traditional Christianity in Europe thrives more on majority approval than on competition and conflict. In West Germany and large parts of Western Europe, church and religious ties are strongly based on the effectiveness of their tradition. However, even if significant sections of the Christian population feel challenged by growing religious plurality and perhaps even threatened by foreign cultures, this does not strengthen their own religious commitment. A counterexample can be found in Italy, where even the comparatively small proportion of non-Christian religious communities and the growing proportion of people without religious affiliation are having a strong mobilizing effect. Highly committed Catholics in particular feel challenged by the increasing public visibility of non-Catholic groups; they present themselves as members of a threatened majority religion that must assert itself against the growing presence of the foreign. The study concludes from this that the perceived threat posed by competing belief systems seems to have a reinforcing effect on religiosity only if it is already deeply rooted in the population.

10) Small religious communities benefit from conflicts with the majority society, especially when they also represent non-religious interests. Evangelical and Pentecostal groups in the US and Latin America use a subcultural identity to distance themselves from the majority society, while at the same time influencing it through social and political interventions, for example on issues such as abortion and homosexuality. The study shows that their relationship with the rest of society is marked by the conflicting simultaneity of separation and connection. This often has an identity-forming effect on members, who can thus apply their faith effectively in socio-political debates.