The global religious landscape has been changing repeatedly over time. There has been a consistent demographic shift affecting all religions across continents. However, the most striking fact, much to my amusement, is the steady rise in the number of religiously unaffiliated people. Across the world, this segment of the population has increased remarkably, while other major religions have experienced growth or decline in varying degrees.
The significant upward momentum of the religiously unaffiliated population sends a stark reminder to major global religions. A Pew Research Survey conducted by the Pew Research Centre highlights these changes, showing how the decade between 2010 and 2020 witnessed a drastic shift in religious demography. Islam has emerged as the fastest-growing religion, while Christianity and other major religions have also experienced upward movement.
During this period, Muslims increased by 347 million. Christians also grew by 122 million believers worldwide, but their growth did not match the rapid pace of the Muslims. Christians remain the largest religious group, accounting for 28.8 percent of the global population, while Muslims represent 25.6 percent.
The survey reports that Buddhists have experienced a notable decline, dropping to 4.1 percent of the global population, a decrease of 0.8 percent from a decade earlier. The religiously unaffiliated have become the third-largest group, holding 24.2 percent of the global population. Hindus have maintained relative stability, recording a modest increase and contributing 14.9 percent of the global population. Largely concentrated in India, Hindus have remained resilient despite social and global challenges.
Among the most populous countries, China has the largest share of religiously unaffiliated people, with around 90 percent identifying as such. India, with approximately 79 percent of its population identifying as Hindu, remains the largest center of Hindu population in the world, while the remaining Hindu population is widely dispersed across other continents.
The survey also points to significant regional changes in Christianity. Although it remains the world’s largest religion, it is facing a noticeable decline in the Americas and Europe, where its long-standing dominance is gradually eroding. Christians, according to the survey, are shrinking in number largely because believers either switch out of the religion or move toward other, more convenient religions with which they can draw ideological and spiritual parallels. This trend is the result of a deep-seated discontent within the framework of Christianity. Christianity, along with its established institutions known as churches, is critically viewed to have widely failed to satisfy the spiritual needs of its followers. Its single religious text, which it claims holds full authority in defining spirituality from multiple perspectives, critics say, has failed to answer the complex questions posed by the faithful. Consequently, religious disaffiliation has become increasingly common within Christian communities, contributing to the growing number of religiously unaffiliated individuals.
Religious switching reveals the level of inconsistency between spiritual values and their practical implementation. Surveys that focus on the trend of leaving the religion into which one is born further illuminate the anomalies that believers experience. Deeply rooted in the spiritual attributes and practices of a particular religion, many followers eventually come to realize that something within them remains unsatisfied. Spiritual evolution in an individual is often the result of a consistent effort to remain in communion with the divine. For those who aspire to cherish a spiritual glimpse of eternity, religions that fail to grant this vision of unity with eternal truth may become barren spaces of ritualistic practices that mechanically bring people together. Institutions through which such practices are sustained can then turn into empty structures, and people gradually lose interest in their once-celebrated sanctity.
This may be one aspect of why Christianity and Buddhism have experienced a serious decline in participation. While 8 percent of the total Christian population chose to leave Christianity, the survey observes that Muslims have largely maintained consistency, though 1.2 percent of followers left Islam. The Muslim population faces internal disengagement similar to that seen among Christians, with a growing number of freethinkers and members of the Ex-Muslim movement emerging within the community. Although the number of Ex-Muslims appears to be increasing, the overall global Muslim population remains largely unaffected. At the same time, the survey finds that nearly an equal number of new entrants are converting to Islam from other religions, thereby maintaining its demographic strength. Muslims across the globe, the survey observes, are understood to maintain higher fertility rates than followers of many other religions.
For Hindus, a similar pattern applies, as the total Hindu population has remained almost stable during this period. This stability is not necessarily the result of a consistent fertility rate; rather, it is observed that many Hindus tend to remain within their religious framework, seeking spiritual fulfillment internally rather than turning elsewhere. The survey also highlights other factors contributing to religious demographic shifts. Mortality rates in certain regions may play a role, and migration, while not directly affecting the global total, can significantly influence religious populations within specific areas. For example, Europe’s Muslim population has grown largely due to migration from predominantly Islamic regions. Migration on such a scale can substantially impact the socio-cultural landscape of host countries. Europe witnessed a significant influx of refugees from Islamic countries, with its Muslim population increasing by approximately 6.2 million during the decade.
This global shift in religious demographics has made the world more religiously diverse than before. Major countries are no longer dominated by a single religious concentration. The Religious Diversity Index published by the Pew Research Centre provides another data illustrating how diversity has increased due to mass migration, religious switching, and various local factors. Among the world’s most populous countries, India ranks fourth in religious diversity, while the United States ranks first. Indonesia, Bangladesh, and Pakistan; countries founded largely on Islamic principles, rank near the bottom, as they have limited religious diversity due to their overwhelmingly Muslim populations. Many of the least diverse nations have nearly homogeneous religious compositions. Such demographic concentration can limit visible pluralism and constrain minority expression. Against this backdrop, India stands out as a constitutional democracy that upholds religious freedom and promotes inclusive development through the principle of “Sabka Saath, Sabka Vikas,” (Together with all, development for all).