According to the Pew Research Centre, the religiously unaffiliated - referring to atheists, agnostics and other people who do not identify with a religion - are declining as a share of the population.
However, the authors project that the religiously unaffiliated will make up the largest group in New Zealand.
In the map above, readers can find out the percentage of individuals following Islam, Christianity, Judaism, Hinduism, Buddhism and folk religions (which include African traditional religions, Chinese folk religions, Native American religions and Australian aboriginal religions) as well as those who do not follow a religion.
All faiths, according to Pew, will see an increase in their share except Buddhism - because of low fertility and ageing population among its followers.
By 2050, Christianity is set to decline further in the UK - and in Europe
A quarter of all Christians - 25.5 per cent to be exact - lived in Europe in 2010. By 2050, this is set to drop to 15.6 per cent and Africa is set to be the continent with the most Christians.
In 2010, nearly 24 per cent of the world's Christians lived in sub-Saharan Africa, by 2050, it will be more than 38 per cent, according to Pew.
For Europe, it will not just be the percentage share but the "absolute number" as well that will fall. As the authors of the Pew report explained: "Europe is the only region where the absolute number of Christians is expected to decline by 2050. Europe's Christian population is projected to fall from 553 million in 2010 to 454 million in 2050."
And worldwide, this means a change in the countries with the highest number of Christians.
"By 2050, the list of the 10 countries with the largest Christian populations is anticipated to change considerably. The United States and Brazil are expected to remain atop the list, but Mexico is projected to fall from third to sixth and Russia is expected to drop from fourth to eighth. Germany and China are not expected to appear on the 2050 list."
The changes will mean the UK, along with Australia, Benin, Bosnia-Herzegovina, France, the Netherlands, New Zealand, the Republic of Macedonia will no longer have a Christian majority in 2050. The chart below shows the predicted decline in the UK's Christian population over a 40-year period.
Islam will be the largest religion in the world in 2100
It is widely known that Islam is increasing globally but despite this increase, by 2050, only two more countries (51 in total) will have a population of Muslims that is more than 50 per cent.
By 2050, the Pew report predicted that 30 per cent (2.8 billion) of the population will identify themselves as Muslim compared to 31 per cent (2.9 billion) identifying themselves as Christian. In Europe, it is suggested that by 2050, 10 per cent of the continent will be Muslim and in the US, it will become the second-largest faith.
According to the report authors, the increase in the Muslim population is because those following the faith are younger and infant mortality rates are falling.
"This significant projected growth is largely due to the young age and high fertility rate of Muslims relative to other religious groups... Muslims have higher fertility levels than the world's overall population between 2010 and 2015."
Currently Muslims make up almost a quarter (23.2 per cent) of the world's population.
The share of the world's Jewish population is expected to remain two per cent
Although there is no change in the share, by 2050, the number of people following Judaism will be 16 million compared to 14 million in 2010.
The report authors also concluded that by 2050, the majority of the Jewish population will live in Israel, noting that already eight out of ten Jews live in either the US or Israel.
Although the numbers provided by Pew can be relied upon, the authors noted that within their calculation of Jewish individuals, they only used data for those who identified as following Judaism.
"They do not include so-called "cultural" or "ethnic" Jews - people who have direct Jewish ancestry and who consider themselves at least partially Jewish but who describe themselves, religiously, as atheist, agnostic or nothing in particular. The worldwide estimate of Jews could be larger if this group were included, or smaller if a narrower definition of who is Jewish (such as an unbroken line of matrilineal Jewish descent) were used."
The number of religiously unaffiliated individuals will fall by 2050
Sixteen per cent of the population was unaffiliated to a religion in 2010 and Pew predicted by 2050, this would fall to 13 per cent, mainly because individuals in this group are older and have less children.
The countries with the most unaffiliated populations were China, Japan and the United States, and Pew noted that in 35 years' time, the increase in unaffiliated individuals would be predominantly in the West.
"In six of these countries [with the highest share of unaffiliated] (Japan, the United States, Vietnam, Germany, France and the United Kingdom), the share of the population that is unaffiliated is expected to increase in the coming decades.
"But the potential growth of the unaffiliated is constrained by the fact that these are all countries with overall populations that are shrinking as a share of the world's people."
In their report, the authors explained that their analysis was based on trends and current figures but that "any events - scientific discoveries, armed conflicts, social movements, political upheavals, natural disasters and changing economic conditions" could alter their predictions.
