There are several different religions
claiming to be the “fastest growing religion”. Such claims vary due to different definitions of “fastest growing”, and whether the claim is worldwide or regional. There are also many unreliable claims and rumours, especially for conversion
rates, that often spread as urban legends
Hard data is difficult to come by.
Different definitions of “fastest growing”
Religions can grow in numbers due to conversion
or due to higher birth rates in a religious group
(assuming that children take on the religion of their parents). Religions in particular countries can grow due to immigration.
So the fastest growing religion could refer to:
- The religion whose absolute number of adherents is growing the fastest (by whatever means).
- The religion which is growing fastest in terms of percentage growth per year (by whatever means).
- The religion which is gaining the greatest number of converts.
Measures counting absolute numbers tend to favour the larger religions; measures counting percentage growth the smaller ones. For example, if a religion had only 10 followers, a single addition would be a 10% increase, and would therefore dwarf the percentage growth rates of the larger religions.
The difficulty of gathering data
Statistics on religious adherence are difficult to gather and often contradictory; statistics for the change of religious adherence are even more so, requiring multiple surveys separated by many years using the same data gathering rules. This has only been achieved in rare cases, and then only for a particular country, such as the American Religious Identification Survey
in the USA, or census data from Australia (which has included a voluntary religious question since 1911). Worldwide data is more difficult to gather than data on a particular country.
Statistics for rates of conversion are the most difficult to gather and the least reliable: they are often distorted by social taboos such as the ban on apostasy in Islam, or the reporting of commitments where the individual does not persist. This means that a lot of the data on growth of religions is derived from birth and immigration rates.
There are a large number of people who self-identify themselves as associated to a specific religion, but who are not religiously active. If, for example, asked to choose between Christianity and other religions they would say they were Christians; if asked to choose between Christianity, other religions and "Not religious", they would say "Not religious". This may make categorization difficult.
In countries with mandatory religions, official statistics will only reflect the official position of the government.
Claims to be the fastest growing religion
Note that it would be an argumentum ad populum
to claim that being the “fastest growing religion” has any logical consequences about the truth of that religion.
Whilst it is possible to find claims that almost any religion is the fastest growing, it is much harder to find ones backed up by scientific data. A selection of the more credible claims are given below, but even these are often contradictory, and most of them only cover a single region of the world.
The World Christian Database (WCD) and it's predecessor the World Christian Encyclopedia has reviewed religious populations around the world and released results of their investigations at various times. Some results are available for a few spread of years - 1970 to 1985, 1990 to 2000, and most recently from 2000 to 2005, recording the percentage growth over these periods. Following is a tabulation of their results:
|3.65% - Bahá'í Faith
||2.65% - Zoroastrianism
||1.84% - Islam |
|2.74% - Islam
||2.28% - Bahá'í Faith
||1.70% - Bahá'í Faith |
|2.34% - Hinduism
||2.13% - Islam
||1.62% - Sikhism |
|1.67% - Buddhism
||1.87% - Sikhism
||1.57% - Hinduism |
|1.64% - Christianity
||1.69% - Hinduism
||1.32% - Christianity |
|1.09% - Judaism
||1.36% - Christianity
||1.09% - Buddhism
||The annual growth in the world population over the same period is 1.41%.
For the 2000-2005 edition, the Carnegie Endowment for International Peace, concluded that high birth rates were the reason for the growth in all six, however the growth of Christianity is also attributed to conversions. A review examining the reliability and bias of the WCD found it "highly correlated with other sources of data" but "consistently gave a higher estimate for percent Christian." In conclusion they found that "on the whole we find that the WCD is reliable.
The Australian Bureau of Statistics
through statistical analysis held Buddhism
to be the fastest growing spiritual tradition/religion in Australia
in terms of percentage gain with a growth of 79.1% for the period 1996 to 2001 (200,000→358,000).
- The U.S. Center for World Mission claimed a growth rate of 2.3% for the period 1970 to 1996, (slightly higher than the world population growth rate at the time). This increased the percentage of Christians from 33.7% to 33.9%.
- The US Department of State estimates that Protestant Christianity may have grown 600% over the last decade in Vietnam.
- The World Christian Database as of 2007 estimated the growth rate of Christianity at 1.32%. High birth rates and conversions were cited as the main reason.
- From the period between 2000 and 2005, Pentecostalism experienced a global growth rate of 488% expanding from 115 million to 588.5 million global adherents. This classes Pentecostalism as the fastest growing religion world wide.
- Using data from the period 2000-2005 the 2006 Christian World Database estimated that by number of new adherents, Christianity was the fastest growing religion in the world with 30,360,000 new adherents in 2006. This was followed by Islam with 23,920,000 and Hinduism with 13,224,000 estimated new adherents in the same period.
The 2001 American Religious Identification Survey
(ARIS) survey, which involved 50,000 participants, reported that the number of participants in the survey identifying themselves as deists
grew at the rate of 717 percent between 1990 and 2001. If this were generalized to the US population as a whole, it would make deism the fastest-growing religious classification in the US for that period, with the reported total of 49,000 self-identified adherents representing about 0.02% of the US population at the time.
No reliable data is available for the number of adherents of Falun Gong
but as this religion was only established in 1992 most of the growth must have been by conversion
. Estimates for the number of adherents for 1999 range from 2 million to 100 million.
The Australian claim for Buddhism above has now been superseded by the 2006 census data, which gives the highest percentage gain to Hinduism
, with a 193% increase over the 15 years from 1991 to 2006. This is, however, from a small base.
Data for Islam reveal that the growing number of Muslims is due primarily to immigration (in the West) and higher birth rates (worldwide).
- In 2006, countries with a Muslim majority had an average population growth rate of 1.8% per year (when weighted by percentage Muslim and population size). This compares with a world population growth rate of 1.12% per year.
- By real growth in terms of new adherents per period Islam was classified as the second fastest growing religion in the world behind Christianity.
- According to the "Pew Forum on Religion & Public Life"
Islam is already the fastest-growing religion in Europe. Driven by immigration and high birthrates, the number of Muslims on the continent has tripled in the last 30 years. Most demographers forecast a similar or even higher rate of growth in the coming decades.
- According to the Carnegie Endowment for International Peace, the World Christian Database as of 2007 estimated the fastest growing of the five largest religion in the world by percentage (not real growth) to be Islam (1.84%). High birth rates were cited as the reason for the growth. The same study concluded that in terms of real growth Islam was not the fastest growing religion.
There is considerable difficulty in ascertaining the number of Muslims and as a result most measurements are inflated.
- The American Religious Identification Survey gives Wicca an average annual growth of 143% / 11,454 for the period 1990 to 2001 (8,000→134,000 - U.S. data / similar for Canada & Australia).
The Islamic Republic of Bosnia and Herzegovina
- The American Religious Identification Survey gave Non-Religious groups the largest gain in terms of absolute numbers - 14,300,000 (8.4% of the population) to 29,400,000 (14.1% of the population) for the period 1990 to 2001 in the USA.
- In Australia, census data from the Australian Bureau of Statistics gives "no religion" the largest gains in absolute numbers over the 15 years from 1991 to 2006. from 2,948,888 (18.2% of the population that answered the question) to 3,706,555 (21.0% of the population that answered the question).