What will the world’s religious population look like in the middle of the twenty-first century? Well, pace Frederick Nietzsche, God will not be dead, at least according to the number of believers in the world. Instead, it will be those of no religious affiliation who will be rarer as a proportion of the population, according to a recent report by the Pew Research Center. But, while the proportion of the world’s population that profess belief in one religion or another will increase from 84 to 87.5 per cent, certain religions will decline. Indeed, the only groups which will increase their share of the world’s population from 2015 to 2060 will be Muslims and Christians.

Drawing on a database of nearly 2500 databases, surveys and population registers, the report predicts that the world’s population in 2016 will have grown by 32 per cent, to 9.6 billion. While almost all of the world’s religious affiliations/groupings, including the “unaffiliated” or “nones”, are expected to grow in absolute terms, only the Christians and Muslims are expected to grow by more than 32% and thus grow their share of the world’s population. Thus, while the numbers of unaffiliated will grow by 3 per cent, to just over 1.2 billion people in 2060, the proportion of the world not adhering to one of the religious groupings will decline from 16 to 12.5 per cent. The unaffiliated will thus be the fourth largest religious grouping in 2060 whereas it is the third largest today. By the middle of the twenty-first century it will have been leap-frogged by the number of Hindus in the world whose share will also decline (from 15.1 to 14.5 per cent) but not as quickly as the “nones”. There will be more Jews and more people adhering to folk religions (for example, traditional African, Chinese, Native American and Aboriginal Australian religions) in 2060 than there are today, but both groups will be slightly less popular relatively than they are today.

In fact, in absolute terms, the only groupings which will decline between now and 2060 are “other relgions” (Baha’is, Jains, Sikhs, Taoists etc) and Buddhists. The latter will decline from half a billion to 461 million people. This is due to low fertility rates and ageing populations in China, Thailand and Japan.

The two largest religions in 2016 were Christianity (31.2 per cent of the world’s population) and Islam (24.1 per cent of the world’s population). They will continue to be the largest religions in 2060, and Christianity will still be the largest religion. But only just. While Christianity will grow by 34% in the years to 2060, this is only just faster than the world’s overall population growth. So, in 2060 31.8 per cent of the world will be Christian, a proportionate growth of only 0.6%. The number of Muslims in the world will grow much more quickly. By 2060 there will be nearly as many Muslims as Christians in the world at 31.1 per cent. This represents a growth rate of 70 per cent in the next four decades. This is due to the relatively younger Muslim population in 2016 and the much higher fertility rates for Muslims globally. This can be seen in the number of babies estimated to be born to Muslim parents. In the five years to 2015 there were 213 million Muslim births, while in the same period there were 223 million Christian births. However by 2030-35 there will be roughly similar numbers of babies born in each religious tradition and by 2055-2060 there will be six million more Muslim than Christian births.

What is largely driving these projections is demography. Muslims, and to a lesser extent Christians, live in younger, more fertile countries, particularly in sub-Saharan Africa. Buddhists and “nones” tend to live in older, less fertile countries like China, Japan or Western Europe. While there is some adjustment in Pew’s projections to take account of religious shifting once a person is an adult, this is far overshadowed by natural change. Thus, in the years 2010-2015, Christianity grew naturally by 116 million people, but decreased due to shifting by nine million. Conversely, the unaffiliated grew by 26 million people naturally and were further boosted by another 8 million shifting when adults. Islam grew by 152 million naturally, but only 0.5 million due to religious shifting.

Marcus Roberts

Marcus Roberts was two years out of law school when he decided that practising law was no longer for him. He therefore went back to university and did his LLM while tutoring. He now teaches contract and...