The fastest growing "religion" in the world is: non-religion.
http://en.wikipedia.org/wiki/Claims_to_be_the_fastest_growing_religion
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.
Buddhism
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).[2]
Christianity
* 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%%.[3]
* The US department of state estimates that Protestant
Christianity may have grown 600%% over the last decade in Vietnam.[4]
Falun Gong
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[5] to 100 million.[6]
Hinduism
The Australian claim for Buddism above has now been superseded by the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.[7] The increase may be due to immigration
of Hindus from India.
Islam
Data for Islam reveal that the growing number of Muslims is due
primarily to immigration (in the West) and higher birth rates
(worldwide). [8].
* 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).[9] This compares with a world population
growth rate of 1.12%% per year.[10]
* According to the "Pew Forum on Religion & Public Life"[11]
“ 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 six fastest growing
religions of the world to be Islam (1.84%%), the Bahá'í Faith (1.7%%),
Sikhism (1.62%%), Jainism (1.57%%), Hinduism (1.52%%), and Christianity
(1.32%%). High birth rates were cited as the reason for the growth.
[12].
Wicca
* 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).[1][13]
Non-Religious
* 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.[1][13].
* 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).[14]
