Religious Belief in the Year 2100

Gina A. Bellofatto

By Gina A. Bellofatto

Projecting religious populations around the globe to 2100 first requires a nod to trends over the previous 200 years. In 1910, those imagining the future of religion generally had a positive outlook, with many believing that religion was an unchallenged fact of life that would continue on for generations to come.

In one sense, this conviction was incorrect, as the world was, by percentage, less religious in 2012 than in 1900. In 1900, 99.8% of the world’s population belonged to a religious tradition and 0.2% were unaffiliated (agnostic or atheist). The year 2012 marked a drop in the world’s religious population to 88.2% and a rise of unaffiliated populations to 11.8%.

In 2100, however, the world will likely be only 9% unaffiliated—more religious than in 2012. The peak of the unaffiliated was in 1970 at around 20%, largely due to the influence of European communism. Since communism’s collapse, religion has been experiencing resurgence that will likely continue beyond 2100.

All the world’s religions are poised to have enormous numeric growth (with the exceptions of tribal religions and Chinese folk-religion), as well as geographic spread with the continuation of migration trends. Adherents of the world’s religions—perhaps particularly Muslims, Hindus, and Buddhists—will continue to settle in the formerly Christian and ever-expanding cities of Europe and North America, causing increases of religious pluralism in these areas.

Christians and Muslims together will encompass two-thirds of the global population—more than 7 billion individuals. In 2100, the majority of the world’s 11.6 billion residents will be adherents of religious traditions.

A child born in 2012 begins his life in a religious world, and when he reaches 88 years of age in 2100, that reality will be even more intensified. No matter what religious tradition he belongs to, if any, he will be immersed in a world populated by the religious and defined by an increasing plurality of theologies, spiritualities, and worldviews, all living at his doorstep.

While this kind of crowded ideological marketplace has the potential for cultural clashes and conflict, it could alternatively serve as an impetus for a new spirit of tolerance and community: Living in a shared, increasingly global society compels people to realize their commonalities and shared interests even in the face of differences in creed.

Gina Bellofatto is a research associate at the Center for the Study of Global Christianity at Gordon-Conwell Theological Seminary in South Hamilton, Massachusetts, and a doctoral student studying world religions and international religious demography at Boston University’s School of Theology.