Christian Denominations
A comparison of major Christian denominations — Trinitarian, Unitarian, and other views of God — with their founding dates, founders, estimated size, and sources.
Christianity has more denominations than perhaps any other religion — commonly estimated in the tens of thousands once every regional and independent body is counted. The table below compares some of the more prominent ones: how each understands the nature of God (Trinitarian, Unitarian, or another view), when and by whom it was founded, roughly how large it is today, and a linked source for each. A chart of the twelve numerically largest follows the table’s introduction below.
Figures are rough, order-of-magnitude estimates, not censuses — compiled from each communion's own reporting where published (e.g. the Vatican, the Lutheran World Federation, the Anglican Communion) and from independent researchers otherwise (e.g. Pew Research / the Center for the Study of Global Christianity for Pentecostalism). Showing the twelve largest by estimated size; the full table below covers all twenty, including smaller and newer movements, with a source for every figure.
| Denomination | Nature of God | Year founded | Founder | Est. adherents | Brief beliefs |
|---|---|---|---|---|---|
| Roman Catholic Church | Trinity | Traditionally 1st century; distinct Western institution after the 1054 Great Schism | Jesus Christ, with St. Peter as first Bishop of Rome (per Catholic teaching) | ~1.36 billion | World's largest Christian body; holds Mary (peace be upon her) as Mother of God but not divine herself, alongside doctrines of her Immaculate Conception and bodily Assumption; recognizes papal authority. |
| Eastern Orthodox Church | Trinity | Traditionally 1st century; distinct Eastern communion after 1054 | Apostolic — no single post-apostolic founder | ~220 million | Rejects papal supremacy; strong emphasis on icons and the unbroken continuity of apostolic tradition. |
| Oriental Orthodox churches (Coptic, Armenian, Syriac, Ethiopian, and others) | Trinity | Distinct communion after the 451 Council of Chalcedon; individual churches earlier (e.g. Armenian Apostolic, state religion from 301) | Varies by church — e.g. St. Mark the Evangelist (Coptic tradition), St. Gregory the Illuminator (Armenian) | ~60 million | Miaphysite Christology (Christ's divine and human natures united as one) — rejected the "two natures" formula agreed at Chalcedon. |
| Assyrian Church of the East | Trinity | Distinct communion after the 431 Council of Ephesus | Apostolic; historically associated with the Christology of Nestorius | ~400,000 | Emphasizes a sharp distinction between Christ's divine and human natures; historically spread across Persia and Central Asia. |
| Lutheran | Trinity | 1517–1521 | Martin Luther | ~75 million | Salvation by faith alone (sola fide) and scripture alone (sola scriptura); rejects papal authority and the sale of indulgences. |
| Reformed / Presbyterian | Trinity | 1536 (Geneva); 1560 (Scotland) | John Calvin; John Knox | ~80 million | Emphasizes God's sovereignty and predestination; governed by elders (presbyters) rather than bishops. |
| Anglican / Episcopal | Trinity | 1534 | King Henry VIII (break from Rome); doctrine later shaped by Archbishop Thomas Cranmer | ~85 million | Retains much Catholic liturgy and a bishop-led structure while affirming Reformation theology. |
| Anabaptist (Mennonite, Amish, Hutterite) | Trinity | 1525 (Zurich); Mennonite branch from 1536; Amish split in 1693 | Conrad Grebel and the Swiss Brethren; Menno Simons (Mennonite); Jakob Ammann (Amish) | ~2.1 million | Believer's (adult) baptism only; pacifism; separation of church and state. |
| Baptist | Trinity | 1609 (Amsterdam) | John Smyth | ~100 million | Believer's baptism by full immersion; congregational governance; wide internal diversity (Southern Baptist, American Baptist, and others). |
| Methodist | Trinity | 1738 | John Wesley (with Charles Wesley) | ~80 million | Emphasizes personal holiness, social reform, and free-will (Arminian) theology over strict predestination. |
| Pentecostal (Assemblies of God, Church of God in Christ, and others) | Trinity | 1906 (Azusa Street Revival); earlier roots at Topeka, 1901 | William J. Seymour (Azusa Street); Charles Parham (earlier Topeka revival) | ~280 million | Emphasizes baptism of the Holy Spirit evidenced by speaking in tongues (glossolalia) and other spiritual gifts. |
| Oneness Pentecostal (United Pentecostal Church, and others) | Other — Modalist ("Oneness"): God is a single person who reveals Himself as Father, Son, and Spirit, not three eternally distinct persons | 1914–1916, splitting from the Assemblies of God | Frank Ewart; Glenn Cook | ~24 million | Baptizes "in the name of Jesus" only, rather than the traditional Trinitarian formula. |
| Seventh-day Adventist | Trinity | 1863 (organized); Millerite roots from the 1830s–40s | Ellen G. White, James White, Joseph Bates | ~22 million | Observes Saturday, the seventh day, as the Sabbath; emphasizes Christ's imminent second coming. |
| Jehovah's Witnesses | Unitarian — God the Father alone is Almighty God; Jesus is Michael the Archangel, God's first creation, not co-eternal with the Father | 1870s (Bible Student movement); renamed 1931 | Charles Taze Russell; reorganized under Joseph Rutherford | ~8.7 million | Rejects the Trinity, blood transfusions, and participation in politics or military service; known for door-to-door evangelism. |
| The Church of Jesus Christ of Latter-day Saints (Mormons) | Other — a Godhead of three distinct, separate divine beings (Father, Son, and Holy Ghost) united in purpose but not in a single being | 1830 | Joseph Smith | ~17.2 million | Restorationist; accepts the Book of Mormon alongside the Bible as scripture; teaches that humans can progress toward godhood. |
| Christian Science (Church of Christ, Scientist) | Other — God as an impersonal divine Principle or Mind; sin, disease, and matter are regarded as ultimately unreal | 1879 | Mary Baker Eddy | Not disclosed by the church; independently estimated well under 100,000 today, down from a reported peak near 268,000 in 1936 | Relies on prayer rather than medicine for healing; central text is Eddy's Science and Health with Key to the Scriptures. |
| Christadelphians | Unitarian — God the Father alone is God; Jesus is His literal son, who did not exist prior to his human birth | Teachings from 1848; name adopted 1864 | John Thomas | ~50,000 | Rejects the Trinity and the natural immortality of the soul; teaches immortality is granted only to the saved. |
| Unitarian Universalism | Historically Unitarian; today non-creedal and theologically pluralistic — many congregations no longer identify as Christian | 1961 (merger); Unitarian roots to 1568 (Transylvania), Universalist roots to 1779 (first congregation, Gloucester, Massachusetts) | No single founder — the American Unitarian Association (1825) merged with the Universalist Church of America | ~150,000 (US/Canada congregational membership) | Historically rejected the Trinity and the doctrine of eternal hell; today welcomes a wide range of beliefs, including humanist and non-theist members. |
| Iglesia ni Cristo | Unitarian — God the Father alone is the one true God; Jesus is a created, exalted man rather than God, though revered as the one mediator | 1914 (Philippines) | Felix Y. Manalo | ~2.3 million (INC does not publish official figures; independently estimated) | Teaches it is the one true church, restored in the "last days"; worships congregationally in large, purpose-built temples. |
| World Mission Society Church of God | Other — believes in both "God the Father" and "God the Mother" as two distinct divine persons | 1964 (South Korea) | Ahn Sahng-hong | ~3.6 million (self-reported by the church; independent verification unavailable) | Observes the Sabbath and biblical feast days; regards a living woman, Zahng Gil-jah, as the Second Coming of Christ and "God the Mother." |
Most of the world’s roughly two billion Christians belong to the Roman Catholic, Eastern/Oriental Orthodox, and mainline or Pentecostal Protestant traditions at the top of this table — all of which affirm the Trinity, whatever else divides them. The Unitarian and “Other” entries further down are numerically much smaller, but are worth including precisely because they show that even the most basic question — whether God is one person or three — has never had a single, universal answer within movements that call themselves Christian. Population figures throughout are necessarily approximate: several groups (Iglesia ni Cristo, the World Mission Society Church of God, Christian Science) do not publish independently verifiable membership statistics, and even well-documented communions count members by different standards (baptized, active, or self-identified).