Major religious groups

The world's principal religions and spiritual traditions may be classified into a small number of major groups, though this is not a uniform practice. This theory began in the 18th century with the goal of recognizing the relative degrees of civility in different societies, but this concept of a ranking order has since fallen into disrepute in many contemporary cultures.

Religious demographics

One way to define a major religion is by the number of current adherents. The population numbers by religion are computed by a combination of census reports and population surveys, in countries where religion data is not collected in census, for example the United States or France. Results can vary widely depending on the way questions are phrased, the definitions of religion used and the bias of the agencies or organizations conducting the survey. Informal or unorganized religions are especially difficult to count.
There is no consensus among researchers as to the best methodology for determining the religiosity profile of the world's population. A number of fundamental aspects are unresolved:

Whether to count "historically predominant religious culture".
Whether to count only those who actively "practice" a particular religion.
Whether to count based on a concept of "self-identification as adherents".
Whether to count only those who expressly self-identify with a particular denomination.
Whether to count only adults, or to include children as well.
Whether to rely on official government-provided statistics.
Whether to use multiple sources and ranges or single "best source".
Largest religious groups

Medium-sized religions

Religion	Followers	Cultural tradition	Founded	References
Shinto	89	Japanese religions	Japan, unknown origin date
Taoism		Chinese religions	China, 2nd century CE
Yoruba Religion		African religions	Yorubaland, unknown origin date
Voodoo	60	African religions	Dahomey, unknown origin date
Sikhism	25–30	Indian religions	Indian subcontinent, 15th century
Mormonism	17.2	Abrahamic religions and New religious movements	USA, 1820s
Judaism	15	Abrahamic religions	Judah, 6th to 5th century BCE
Spiritism		Abrahamic religions and New religious movements	France, 19th century
Mu-ism		Korean religions	Korea, unknown origin date
Unification Church	10	Abrahamic religions and New religious movements	South Korea, 1954
Baháʼí Faith		Abrahamic religions and New religious movements	Persia, 19th century
Confucianism		Chinese religions	China, 6th to 5th century BCE
Sarnaism	5	Indian religions	Chota Nagpur Plateau, Unknown
Jainism		Indian religions	Indian subcontinent, 7th to 9th century BCE
Cheondoism		Korean religions and New religious movements	Korea, 19th century
World Mission Society Church of God	3.9	Abrahamic religions and New religious movements	South Korea, 1964
Hoahaoism		Vietnamese religions	Vietnam, 20th century
Iglesia ni Cristo	2.8	Abrahamic religions and New religious movements	Philippines, 1913
Ravidassia	1.5–2	Indian Religions and New religious movements	Indian subcontinent, 2010
Caodaism		Vietnamese religions	Vietnam, 20th century
Tenriism		Japanese religions	Japan, 19th century
Druze	1	Abrahamic religions	Egypt, 9th century
Tengrism	1	Animism	Central Asia, unknown origin date
Rastafari	1	Abrahamic religions and New religious movements	Jamaica, 1930s

Small-sized religion

By region

Religions by country according to The World Factbook – CIA
Religion by region
Religion in Africa
Religion in Antarctica
Religion in Asia
*Religion in the Middle East
*Muslim world
Religion in Europe
*Religion in the European Union
*Christian world
Religion in North America
Religion in Oceania
Religion in South America
Trends in adherence

	1970–1985	1990–2000	2000–2005	1970–2010
Baháʼí Faith	3.65	2.28	1.70	4.26
Buddhism	1.67	1.09		2.76
Christianity	1.64	1.36	1.32	2.10
Confucianism				0.83
Hinduism	2.34	1.69	1.57	2.62
Islam	2.74	2.13	1.84	4.23
Jainism				2.60
Judaism	1.09			-0.03
Sikhism		1.87	1.62	3.08
Shinto				-0.83
Taoism				9.85
Zoroastrianism				2.5
unaffiliated				0.37

Maps of self-reported adherence

Classification

Religious traditions fall into super-groups in comparative religion, arranged by historical origin and mutual influence. Abrahamic religions originate in the Middle East, Indian religions in the Indian subcontinent and East Asian religions in East Asia. Another group with supra-regional influence are Afro-American religion, which have their origins in Central and West Africa.

Middle Eastern religions:
* Abrahamic religions are the largest group, and these consist mainly of Judaism, Christianity, Islam, and the Baháʼí Faith. They are named for the Hebrew patriarch Abraham, and are unified by the practice of monotheism. Today, at least 3.8 billion people are followers of Abrahamic religions and are spread widely around the world apart from the regions around East and Southeast Asia. Several Abrahamic organizations are vigorous proselytizers. Abrahamic religions with fewer adherents include the Baháʼí Faith, the Druze faith, Samaritanism, and Rastafari.
* Iranian religions, partly of Indo-European origins, include Zoroastrianism, Yazdânism, Uatsdin, Yarsanism, Manichaeism, and Yazidism.
* Gnosticism, including historical traditions of Mandaeism, which is still alive in the Middle East and diaspora.
Eastern religions:
* Indian religions, originated in Greater India and they tend to share a number of key concepts, such as dharma, karma, reincarnation among others. They are of the most influence across the Indian subcontinent, East Asia, Southeast Asia, as well as isolated parts of Russia. The main Indian religions are Hinduism, Jainism, Buddhism and Sikhism. In 2010 Ravidassia religion was separated from Sikhism.
* East Asian religions consist of several East Asian religions which make use of the concept of Tao, Đạo or Dō. They include many Chinese folk religions, Taoism and Confucianism, as well as Vietnamese, Korean and Japanese religions, which are influenced by Chinese religious thought.
Indigenous ethnic religions, found on every continent, now marginalized by the major organized faiths in many parts of the world or persisting as undercurrents of major religions. Includes traditional African religions, Asian shamanism, Native American religions, Austronesian and Australian Aboriginal traditions, Chinese folk religions, and postwar Shinto. Under more traditional listings, this has been referred to as "paganism" along with historical polytheism.
* African religions:
** The religions of the tribal peoples of Sub-Saharan Africa, but excluding ancient Egyptian religion, which is considered to belong to the ancient Middle East;
** African diasporic religions practiced in the Americas, imported as a result of the Atlantic slave trade of the 16th to 18th centuries, building on traditional religions of Central and West Africa.
New religious movement is the term applied to any religious faith which has emerged since the 19th century, often syncretizing, re-interpreting or reviving aspects of older traditions such as Ayyavazhi, Mormonism, Ahmadiyya, Jehovah's Witnesses, polytheistic reconstructionism, and so forth.
History of religious categories

Christian categorizations

Initially, Christians had a simple dichotomy of world beliefs: Christian civility versus foreign heresy or barbarity. In the 18th century, "heresy" was clarified to mean Judaism and Islam; along with paganism, this created a fourfold classification which spawned such works as John Toland's Nazarenus, or Jewish, Gentile, and Mahometan Christianity, which represented the three Abrahamic religions as different "nations" or sects within religion itself, the "true monotheism."
Daniel Defoe described the original definition as follows: "Religion is properly the Worship given to God, but 'tis also applied to the Worship of Idols and false Deities." At the turn of the 19th century, in between 1780 and 1810, the language dramatically changed: instead of "religion" being synonymous with spirituality, authors began using the plural, "religions", to refer to both Christianity and other forms of worship. Therefore, Hannah Adams's early encyclopedia, for example, had its name changed from An Alphabetical Compendium of the Various Sects... to A Dictionary of All Religions and Religious Denominations.
In 1838, the four-way division of Christianity, Judaism, Mahommedanism and paganism was multiplied considerably by Josiah Conder's Analytical and Comparative View of All Religions Now Extant among Mankind. Conder's work still adhered to the four-way classification, but in his eye for detail he puts together much historical work to create something resembling the modern Western image: he includes Druze, Yazidis, Mandaeans, and Elamites under a list of possibly monotheistic groups, and under the final category, of "polytheism and pantheism", he listed Zoroastrianism, "Vedas, Puranas, Tantras, Reformed sects" of India as well as "Brahminical idolatry", Buddhism, Jainism, Sikhism, Lamaism, "religion of China and Japan", and "illiterate superstitions" as others.
The modern meaning of the phrase "world religion", putting non-Christians at the same level as Christians, began with the 1893 Parliament of the World's Religions in Chicago. The Parliament spurred the creation of a dozen privately funded lectures with the intent of informing people of the diversity of religious experience: these lectures funded researchers such as William James, D. T. Suzuki, and Alan Watts, who greatly influenced the public conception of world religions.
In the latter half of the 20th century, the category of "world religion" fell into serious question, especially for drawing parallels between vastly different cultures, and thereby creating an arbitrary separation between the religious and the secular.