A significant portion of adults worldwide—up to a fifth or more in some countries—have left the religious traditions in which they were raised, with Christianity and Buddhism experiencing substantial losses due to religious switching. Meanwhile, the number of people identifying as religiously unaffiliated has been rising, according to Pew Research Center surveys conducted across 36 countries, involving nearly 80,000 respondents.
Understanding Religious Switching
Religious switching, as defined in this report, refers to a shift from the religious group in which a person was raised during childhood to their current religious identity in adulthood. The term “religious switching” is used instead of “conversion” since these changes occur in multiple directions, including from a religious identity to being unaffiliated.
The study considers transitions between major religious categories—such as from Buddhist to Christian or Hindu to unaffiliated—but does not track changes within a single religion, such as switching from one Christian denomination to another.
Global Variations in Religious Switching
The frequency of religious switching varies significantly by region. In some countries, changes in religious identity are rare. In India, Israel, Nigeria, and Thailand, at least 95% of adults still identify with the religious group they were raised in.
Conversely, religious switching is more prevalent in East Asia, Western Europe, North America, and South America. For instance, 50% of adults in South Korea, 36% in the Netherlands, 28% in the United States, and 21% in Brazil have left their childhood religion.
Religious Affiliations Gained Through Switching
Most religious switching has resulted in people joining the religiously unaffiliated category, which includes those identifying as atheists, agnostics, or “nothing in particular.” This pattern suggests that religious disaffiliation—people leaving their childhood faith and no longer identifying with any religion—is the dominant trend.
Many of those who disaffiliate were raised as Christians. For example, 29% of adults in Sweden were raised as Christians but now identify as atheists, agnostics, or religiously unaffiliated.
Buddhism has also seen losses due to disaffiliation. In Japan, 23% of adults who were raised Buddhist no longer identify with any religion, while in South Korea, this figure stands at 13%.
However, not all religious switching leads to disaffiliation. Some people move in the opposite direction. South Korea has the highest share of individuals (9%) who were raised without a religion but have since adopted one, with 6% of all South Korean adults saying they were raised unaffiliated but are now Christians.
In addition, about one in ten or more adults in Singapore (13%), South Africa (12%), and South Korea (11%) have switched between two religions.
Major Religious Trends by Country
Christianity, the world’s largest and most widespread religion, has historically been the predominant faith in 25 of the surveyed countries.
Islam, the second-largest religion globally, is predominant in six surveyed countries: Bangladesh, Indonesia, Malaysia, Nigeria, Tunisia, and Turkey. Nigeria is considered a religiously divided country, with both Christianity and Islam playing dominant roles.
Buddhism has historically been predominant in five countries surveyed: Japan, Singapore, Sri Lanka, South Korea, and Thailand. South Korea is unique in that both Buddhism and Christianity have had significant influence.
Hinduism is predominant in India, while Judaism is predominant in Israel.
Religious Groups Experiencing the Largest Losses
A key metric in analyzing religious switching is the net gain or loss of adherents, measured by comparing the number of people who have left a religion to those who have joined.
In most surveyed countries, Christianity has the highest ratio of people leaving versus joining, indicating the largest net losses. In Germany, for example, for every one person who has converted to Christianity, nearly 20 Germans have left the faith (a ratio of 19.7 to 1.0).
However, in some countries, Christianity has seen net gains. In Singapore, for every one person who has left Christianity, about three others have joined (a ratio of 1.0 to 3.2). In Nigeria, Christianity’s ratio of leaving to joining is balanced at 1.0 to 1.0.
Buddhism is also experiencing net losses due to disaffiliation in countries like Japan, Singapore, and South Korea, although not as severely as Christianity. In Japan, where Buddhism has experienced the greatest loss, the ratio of leaving to joining is 11.7 to 1.0.
The Biggest Gainer: The Religiously Unaffiliated
The religiously unaffiliated category has seen the most significant net gains from switching. In countries where a substantial portion of the population identifies as unaffiliated, far more people have left religion than have joined one.
For example, in Italy, the ratio of people leaving religion to those joining one is 1.0 to 28.7. This means that for every one person raised without a religion who later adopts one, nearly 29 people raised in a religion now identify as unaffiliated.
However, not all countries follow this trend. In Hungary, for every person who has become unaffiliated, nearly two others were raised without a religion but have since adopted one (a ratio of 1.9 to 1.0), with most of them becoming Christians.
Demographic Differences in Religious Switching
Age Differences
In most surveyed countries, younger and older adults have switched religions at similar rates. In Singapore, for instance, 29% of both younger adults (ages 18–34) and older adults (ages 50 and older) have switched religions.
However, in 13 countries—particularly in Latin America, Europe, and North America—younger adults are more likely than older adults to have switched religions. In Spain, 48% of adults aged 18–34 have changed their religious identity since childhood, compared to 36% of those aged 50 and older. Similarly, in Colombia, 34% of young adults have switched religions, compared to only 14% of the oldest adults.
In contrast, Australia presents a different trend, with younger adults being slightly less likely to switch religions than older adults (32% vs. 37%).
Regardless of age, most switching results in disaffiliation, with many younger people leaving Christianity. In Colombia, 26% of adults aged 18–34 who were raised Christian no longer identify with any religion, compared to just 9% of those aged 50 and older.
Some of these patterns may indicate long-term secularization trends, particularly in countries like Spain, Canada, Italy, and the U.S. However, it is also possible that some older adults who are now religious switched in and out of religion earlier in life.
Education and Religious Switching
In most countries, religious switching rates do not differ significantly based on education level. However, in 12 of the surveyed countries, people with higher levels of education are more likely to have switched religions.
The Netherlands shows the largest disparity: 42% of highly educated Dutch adults (those with a postsecondary degree) have changed religions, compared to 29% of those with lower levels of education.
Gender Differences
In most surveyed countries, men and women switch religions at similar rates. In South Korea, for example, 51% of women and 50% of men have changed their religious identity.
However, in six countries, men are significantly more likely than women to have switched religions. As with age and education differences, much of this switching involves disaffiliation, with people leaving Christianity or, in Japan, Buddhism.
Key Takeaways
- Most people who currently identify as Christian were raised Christian, though Christianity has seen significant losses due to switching.
- The religiously unaffiliated category has grown the most, largely due to people leaving Christianity or Buddhism.
- Buddhism has seen declines in some countries but has remained stable in others.
- Religious switching into and out of Islam is relatively low in most surveyed countries.
- Judaism has high retention rates in both Israel and the U.S.
- Nearly all people raised Hindu in India and Bangladesh still identify as Hindu.
These trends highlight ongoing religious shifts across the globe, with secularization playing a major role in many regions.