Major religious groups

• 1. Introduction

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  Major religious groups are something most people think they understand. After all, Christianity, Islam, Hinduism, Buddhism: these words get spoken at school, in the news, in daily conversation. But the very concept of sorting the world's spiritual traditions into a ranked list is, by itself, a story with a beginning, a controversy, and an unresolved ending.

  It began in the 18th century, with European scholars who wanted to rank societies by what they called degrees of civility. Religion was a measuring stick. That idea has since fallen into disrepute in many parts of the world. Yet the project of counting and classifying faith communities never stopped. It just got more complicated.

  Who counts as a member of a religion? Do you count children? Do you count people who were born into a tradition but never actively practice it? Do you count based on what someone says when surveyed, or only when a government census asks the question directly? These questions have no agreed answers among researchers today. The Pew Research Centre's 2025 report put Christians at 2.3 billion people, or 28.8 percent of the world's population. That figure alone reflects dozens of methodological choices baked into every survey and census that fed into it.

• 2. The Numbers Problem

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  Pew Research Centre's 2025 report, covering changes from 2010 to 2020, offers one of the most detailed recent snapshots. Christians numbered 2.3 billion, representing 28.8 percent of the global population. Muslims came next at 2 billion, or 25.6 percent. Those who are religiously unaffiliated made up 1.9 billion people, a striking 24.2 percent. Hindus numbered 1.2 billion at 14.9 percent, while Buddhists reached 300 million, or 4.1 percent.

  Countries handle this data collection very differently. In the United States and France, religion data is not collected in census forms at all. Researchers there must rely on population surveys instead. Results can vary widely depending on how questions are phrased, which definition of religion the survey applies, and which organization is doing the asking.

  Informal or unorganized religions are especially hard to count. A person who follows folk traditions alongside a named faith, or who participates in indigenous rites with no formal institution, may not show up clearly in any column. Researchers have never reached a consensus on whether to count historically predominant cultural identities, whether to include only active practitioners, and whether to rely on government-provided statistics or seek multiple independent sources.

• 3. Where Religions Come From

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  Abrahamic religions trace their origins to Judaea and the broader Middle East, and they are named for the Hebrew patriarch Abraham. They are bound together by monotheism, the worship of a single God. At least 3.8 billion people belong to one Abrahamic tradition or another. Christianity emerged around the 30th year of the Common Era. Islam followed in the Hejaz region of the Middle East around 610 CE. Judaism's own roots stretch back to the kingdom of Judah, roughly the 6th to 5th century BCE.

  The Indian subcontinent gave rise to a separate cluster of traditions that tend to share concepts such as dharma, karma, and reincarnation. Hinduism dates to roughly the 20th to 17th century BCE, making it among the oldest of the traditions still practiced at scale. Buddhism emerged on the Indian subcontinent around the 5th century BCE. Sikhism developed in the 15th century, and as recently as 2010, Ravidassia religion separated from Sikhism as a distinct faith.

  East Asian religions draw on the concept of the Tao. Chinese, Vietnamese, Korean, and Japanese religious traditions all share that conceptual inheritance, even as they developed into distinct forms. Taoism as an organized religion traces to 2nd century CE China. Confucianism grew from the 6th to 5th century BCE in China as well. Then there are the indigenous ethnic religions found on every continent, now often marginalized by the major organized faiths or absorbed as undercurrents within them. These include traditional African religions, Asian shamanism, Native American religions, and Australian Aboriginal traditions.

• 4. The Medium and the Small

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  Shinto, with around 89 million followers, is among the largest of what might be called medium-sized religions. Its origin date is listed as unknown. Yoruba religion and Voodoo both trace to African traditions. Voodoo, with around 60 million followers, has roots in the kingdom of Dahomey. Sikhism, with 25 to 30 million followers, originated on the Indian subcontinent in the 15th century.

  The Unification Church, founded in South Korea in 1954, counts around 10 million members. The World Mission Society Church of God, also founded in South Korea, was established in 1964 and claims 3.9 million followers. Iglesia ni Cristo was founded in the Philippines in 1913, and today counts 2.8 million adherents. Rastafari, emerging from Jamaica in the 1930s, has around 1 million followers.

  Among small-sized religions, Wicca was established in the United Kingdom in 1954 and now has around 800,000 practitioners. Zoroastrianism, one of the world's oldest revealed religions with roots in Iran dating to the 16th to 14th century BCE, today numbers only around 205,000 followers. Rodnovery, a modern pagan movement reviving Slavic traditions, emerged in Eastern Europe in the 1930s-1950s and may have between 22,000 and 777,000 adherents, depending on how membership is counted. Samaritanism, with origins in Judah going back to the 6th to 5th century BCE, now numbers only around 900 people.

• 5. How the Categories Were Built

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  Before the 18th century, Christian writers used a simple binary: Christian civility on one side, foreign heresy or barbarity on the other. By the 18th century, "heresy" was refined to mean specifically Judaism and Islam. Added to paganism, this created a fourfold classification. It shaped works like John Toland's Nazarenus, which treated the three Abrahamic traditions as different nations or sects within a single "true monotheism."

  Daniel Defoe captured the older view directly. He wrote that religion is properly the worship given to God, but is also applied to the worship of idols and false deities. Between 1780 and 1810, the language changed dramatically. Authors began using the plural: "religions," not "religion." Hannah Adams's early reference work reflects this shift. Its title was changed from An Alphabetical Compendium of the Various Sects to A Dictionary of All Religions and Religious Denominations.

  In 1838, Josiah Conder's Analytical and Comparative View of All Religions Now Extant among Mankind multiplied the fourfold system considerably. Conder still worked within the four-way frame, but he included Druze, Yazidis, Mandaeans, and Elamites among possibly monotheistic groups. Under polytheism and pantheism, he listed Zoroastrianism, the Vedas, Buddhism, Jainism, Sikhism, Lamaism, the religion of China and Japan, and what he called illiterate superstitions. It was a rough sketch, but it resembles the structure still used today.

• 6. The Parliament That Changed Everything

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  The modern meaning of "world religion" as a category that places non-Christians at the same level as Christians has a specific birthdate: the 1893 Parliament of the World's Religions, held in Chicago. Before that gathering, the comparative framework was still largely hierarchical, with Christianity implicitly at the top.

  The Parliament prompted the creation of a dozen privately funded lecture series designed to inform the public about the diversity of religious experience. Those lectures went on to fund researchers including William James, D. T. Suzuki, and Alan Watts, each of whom shaped how ordinary people understood traditions beyond their own.

  In the latter half of the 20th century, the category of world religion came under serious challenge from scholars, especially for drawing parallels between vastly different cultures. The charge was that naming something a world religion creates an arbitrary line between the religious and the secular, and forces varied traditions into a single analytical container that distorts all of them. That critique has not stopped the counting. It has just made the counters more cautious. Today's trend data shows Neopaganism growing at around 7.03 percent in the 1970-1985 period, a rate that outpaced every other tradition tracked in the same window.