Definition and scope

Religion refers to human orientations toward what is regarded as sacred or ultimate, typically expressed through beliefs, rituals, moral norms, and institutional life; this spans theistic and non-theistic traditions and includes scriptural canons, authority structures, and devotional practices such as prayer, meditation, and worship, as summarized by Encyclopaedia Britannica and philosophical surveys of the concept. Britannica; Stanford Encyclopedia of Philosophy.

Etymology and concept formation

The modern term derives from Latin religio, which in classical usage denoted scrupulous regard, obligation, or devotion, later extended in medieval Latin to describe vowed communal orders and, in early modern Europe, generalized as a taxon for diverse traditions (e.g., Christianity, Islam, Hinduism). Contemporary scholarship tracks this semantic expansion and debates whether “religion” has an essence or functions as a family-resemblance category. Stanford Encyclopedia of Philosophy; Britannica.

Historical development

Archaeological and textual records attest to ritual specialists, cults, and myths in ancient civilizations; later transformations during the so‑called Axial Age (c. 8th–3rd centuries BCE) saw new universalizing doctrines and ethical-philosophical systems across Eurasia, a period named and theorized by Karl Jaspers and subsequently debated in political and historical scholarship. Encyclopedia.com; Cambridge Core—Review of Politics.

Major types and beliefs

Scholars commonly distinguish monotheism (belief in one God), polytheism (many gods), and various non-theistic or transpersonal orientations; animism denotes belief in spiritual beings or forces active in human affairs, while totemism links kin groups to emblematic species through taboo and ritual. These categories describe recurrent patterns but often co‑exist or blend within traditions. Britannica—Monotheism; Britannica—Polytheism; Britannica—Animism; Britannica—Totemism.

Practices, symbols, and institutions

Religious life typically features rites of passage, calendrical festivals, sacrifice, prayer, pilgrimage, and ascetic disciplines; symbolic systems enact and transmit cosmological and moral meanings and are sustained by clergy, monastic orders, congregations, and movement organizations. Classic ritual theory and anthropology analyze how symbols “thicken” cultural meaning and structure practice. Britannica; [Clifford Geertz, The Interpretation of Cultures](book://Clifford Geertz|The Interpretation of Cultures|Basic Books|1973).

Social-scientific interpretations

Sociology and anthropology have proposed influential accounts. Émile Durkheim defined religion as a unified system of beliefs and practices relative to sacred things that unites adherents into a moral community (“Church”), emphasizing the sacred–profane distinction and collective rites. University of Chicago—Durkheim summary. Max Weber traced religion’s comparative ethical logics and their social consequences, including analyses of ascetic Protestantism and capitalist rationalization, and introduced “disenchantment” to describe modernity’s erosion of enchanted worldviews. Britannica—Protestant Ethic; Britannica—Disenchantment.

Philosophy of religion and definition debates

Philosophy of religion examines arguments about divine reality, religious language, pluralism, faith and reason, and the nature of religion itself; contemporary surveys note the absence of consensus on necessary and sufficient conditions for “religion,” favoring pragmatic or family-resemblance approaches. Stanford Encyclopedia of Philosophy—Philosophy of Religion; Stanford Encyclopedia of Philosophy—Concept of Religion.

Demography and change

Global affiliation remains high but is shifting. Between 2010 and 2020, Christians increased in absolute numbers to about 2.3 billion yet declined as a share of world population (to 28.8%); Muslims grew fastest, rising to 25.6%; the religiously unaffiliated (“nones”) expanded to 24.2% due largely to religious switching; Hindus held around 14.9%; Buddhists declined in number to roughly 324 million (4.1%); Jews remained near 0.2%; all other religions together stayed near 2.2%. Sub‑Saharan Africa now hosts the largest number of Christians, surpassing Europe. Pew Research Center, June 9, 2025.

Religion, law, and human rights

International norms protect freedom of thought, conscience, and religion. Article 18 of the Universal Declaration of Human Rights (1948) guarantees the right to change religion or belief and to manifest it individually or collectively in public or private; Article 18 of the International Covenant on Civil and Political Rights (1966) affirms similar protections with limited, lawful restrictions on manifestation. Universal Declaration of Human Rights; OHCHR—ICCPR overview.

Modernization, secularization, and public religion

Modern social theory links industrialization and bureaucratization to secularization and rationalization, while empirical trajectories vary by region. Scholarship differentiates among institutional differentiation (state–religion separation), changes in individual belief/practice, and the (de)privatization of religion, with comparative case studies documenting renewed public religious engagement. Britannica—Modernization: Secularization and rationalization; Georgetown Berkley Center—Casanova, Public Religions in the Modern World; University of Chicago Press—Casanova.

Cognitive and evolutionary approaches

The cognitive science of religion investigates how ordinary mental systems (e.g., agency detection, memory for minimally counterintuitive concepts, ritual psychology) dispose humans toward religious representations and practices; textbooks and handbooks synthesize empirical findings and ongoing debates about function versus byproduct hypotheses. Routledge—An Introduction to the Cognitive Science of Religion; Bloomsbury—Religion Explained? The CSR after 25 Years; Oxford Handbook of the Cognitive Science of Religion.

Key terms and cross-links in the study of religion

Foundational terms used across disciplines include sacred/profane (Durkheim), rationalization and Secularization (Weber and successors), symbol and meaning (Geertz), and rights of conscience (Universal Declaration of Human Rights). University of Chicago—Durkheim summary; Britannica—Disenchantment; Berkley Center—Casanova; UN—UDHR.

Examples and families of traditions

Reference works conventionally group traditions such as Hinduism, Buddhism, Judaism, Christianity, and Islam alongside East Asian, indigenous, and new religious movements; these families vary widely in doctrines (e.g., monotheism, non-theism), institutions (e.g., churches, sanghas), and ritual repertoires, and they have complex histories of interaction and syncretism. Britannica.