What are the world's major religions?

Scholars usually group the world's religions by size and by family resemblance. The four largest by number of adherents are Christianity, with roughly 2.3 billion followers; Islam, with about 2 billion; Hinduism, with around 1.2 billion; and Buddhism, with several hundred million. Beyond these sit Judaism, Sikhism, the Baha'i Faith, Jainism, Shinto, Daoism, and hundreds of Indigenous and folk traditions. A common shorthand sorts them into families. The Abrahamic religions (Judaism, Christianity, Islam) trace themselves to the patriarch Abraham and worship one God, while the Dharmic or Indian religions (Hinduism, Buddhism, Jainism, Sikhism) share concepts like karma and rebirth. East Asian traditions such as Confucianism and Daoism form a third loose cluster. Together these faiths account for most people alive today.

The very idea of "world religions" is a relatively modern, Western-made lens, and it fits some traditions better than others. Christianity and Islam are creedal and missionary: membership hinges on professed belief, and both actively seek converts. Hinduism, by contrast, is less a single doctrine than a vast family of practices, deities, and philosophies with no founder or central authority. Some traditions center on orthodoxy, or right belief; others on orthopraxy, or right practice, with Judaism and Islam emphasizing law and observance as much as theology. Many Indigenous and folk religions are woven so tightly into a people's culture that separating "religion" from everyday life makes little sense. The tidy list of major faiths, in other words, flattens genuinely different kinds of things into one convenient shape.

Geography still shapes belief. Christianity is now most vibrant in sub-Saharan Africa and Latin America rather than its old European heartland; Islam is concentrated across North Africa, the Middle East, and South and Southeast Asia, with Indonesia the largest Muslim-majority country. Hinduism is overwhelmingly Indian, while Buddhism spans East and Southeast Asia. A fast-growing group is the religiously unaffiliated, the so-called "nones," who number well over a billion and include atheists, agnostics, and people who simply claim no religion. Between 2010 and 2020 Islam grew fastest of any major group, driven mainly by younger populations and higher birth rates, and demographers expect it to keep closing on Christianity in size. Religion also remains entangled with law, holidays, diet, dress, art, and conflict across much of the globe, even where formal observance is declining.

Myth: the world's biggest religions are shrinking everywhere. Reality: although much of Europe is secularizing, Christianity and Islam continue to grow worldwide, largely through birth rates. Myth: Hinduism is straightforwardly polytheistic. Reality: many Hindus regard the many gods as faces of one ultimate reality, and its traditions span monotheistic, pantheistic, and non-theistic views. Myth: Buddhism has no gods and is "just a philosophy." Reality: most Buddhists engage in devotion and honor numerous buddhas, bodhisattvas, and deities. Myth: the religiously unaffiliated are all atheists. Reality: most so-called "nones" hold spiritual or supernatural beliefs and simply reject organized religious labels rather than denying anything divine.