Here’s a comprehensive reference guide of major Christian denominations, combining histories, membership, beliefs, and growth trends, all in paragraph form:

The Southern Baptist Convention (SBC) is the largest Protestant denomination in the U.S., founded in 1845 over a split with northern Baptists regarding slavery. The SBC emphasizes personal conversion, believer’s baptism, biblical authority, and conservative positions on social issues such as abortion, same-sex marriage, and women in pastoral leadership. With over 13 million members, it remains culturally and politically influential, particularly in the southern United States. Membership has declined slowly in recent years, mainly due to generational shifts and urban migration.

The Methodist movement began in 18th-century England with John and Charles Wesley, who sought to revive the Anglican Church through disciplined Bible study, personal holiness, and social outreach. Methodism arrived in America during the colonial period and officially became independent at the 1784 Christmas Conference in Baltimore. The denomination split over slavery in the 19th century but later reunited, eventually forming the United Methodist Church (UMC) in 1968. Today, Methodism emphasizes personal faith, social justice, and education, and the UMC has struggled with internal divisions over LGBTQ+ inclusion while continuing to ordain women and engage in global missions. Membership has declined in recent decades, particularly in the U.S., reflecting broader trends among mainline Protestant churches.

The Evangelical Lutheran Church in America (ELCA) was established in 1988 through the merger of several American Lutheran bodies with roots in German and Scandinavian immigration. The ELCA embraces modern, progressive stances, including ordination of women and LGBTQ+ clergy, and recognizes same-sex marriage. It emphasizes Scripture and tradition, sacraments, and social justice activism, with about 3 million members in the U.S. Membership has declined slowly, similar to other mainline Protestant groups.

The National Baptist Convention, USA, Inc. (NBCUSA), founded in 1895, is the largest historically Black denomination, with about 5 million members. It emerged from African American Baptists seeking autonomy from white-dominated churches and became a key institution in education, civil rights, and community development. NBCUSA congregations vary in theology and social stance but are generally conservative on sexual ethics while strongly advocating for racial justice. Membership has remained generally stable, though some urban congregations face declines.

The Assemblies of God (AG), founded in 1914, is the largest Pentecostal denomination in the U.S. It grew out of the early 20th-century Pentecostal revival movement, emphasizing baptism in the Holy Spirit, speaking in tongues, divine healing, and evangelism. The AG maintains conservative social values, opposes abortion and same-sex marriage, and ordains both men and women as pastors. Today, it has about 3 million U.S. members and over 70 million worldwide, with rapid growth, especially in Latin America, Africa, and Asia.

The Roman Catholic Church traces its roots to the apostles, with the Pope as the Bishop of Rome and supreme earthly authority. It emphasizes Scripture and Tradition, seven sacraments, salvation through faith and works, and the Eucharist as the real presence of Christ. Historically central in Western Europe, it experienced the Protestant Reformation in the 16th century and modernized aspects of worship during Vatican II (1962–1965). With about 1.3 billion members worldwide, the Catholic Church remains socially conservative on abortion, same-sex marriage, and women’s ordination while maintaining vast global influence in education, healthcare, and humanitarian efforts. In the U.S., membership and weekly attendance have declined gradually, particularly among younger adults.

The Eastern Orthodox Church split from the Roman Catholic Church in 1054 (Great Schism) over papal authority, cultural differences, and theological disputes. It emphasizes Scripture and Holy Tradition, theosis (union with God), sacraments, conciliar leadership, and mystical, highly ritualized worship. Priests may marry before ordination, while bishops are celibate. With around 220–260 million members worldwide, it is organized into national churches, including Greek, Russian, and Serbian Orthodox, primarily in Eastern Europe, Russia, and the Middle East. Membership is stable, with some growth in diaspora communities.

The Oriental Orthodox Churches separated from both Catholic and Eastern Orthodox bodies after the Council of Chalcedon in 451 AD due to disagreements over Christology. They maintain ancient liturgies, monastic traditions, and cultural distinctiveness. Major bodies include the Coptic Orthodox (Egypt), Armenian Apostolic, Ethiopian Orthodox, Syriac Orthodox, Eritrean Orthodox, and Malankara Orthodox (India). With about 60 million members worldwide, they continue a historic tradition while facing persecution in some regions. Membership has remained stable, with growth in diaspora communities.

The Church of Jesus Christ of Latter-day Saints (LDS or Mormons) was founded in 1830 by Joseph Smith in New York, based on modern revelation and the Book of Mormon. It emphasizes missionary work, family-centered theology, and strict moral standards, including abstention from alcohol and premarital sex. Following early persecution, members migrated west to settle in Utah. Today, the LDS Church has about 6.8 million U.S. members and over 16 million worldwide, with steady growth driven by missionary programs and high retention of young adults.

Jehovah’s Witnesses originated in the late 19th century under Charles Taze Russell. They reject the Trinity, focus on God’s Kingdom as the solution to world problems, abstain from political involvement and military service, and practice door-to-door evangelism. They avoid blood transfusions and traditional Christian holidays. There are about 1.3 million active U.S. members and over 8 million worldwide. Membership is relatively stable but with declining retention in developed countries.

The Seventh-day Adventist Church emerged from the Millerite movement in 19th-century New England and was officially organized in 1863. It emphasizes Saturday Sabbath observance, healthy living, holistic education, and missionary work. Adventists adhere to conservative dietary principles, Bible study, and prophecy. Today, there are about 1.2 million U.S. members and over 25 million worldwide, with steady growth, particularly in Africa, Asia, and Latin America, supported by extensive educational and healthcare networks.

Overall Trends

Across the U.S., mainline Protestant churches and traditional Roman Catholic congregations are declining in membership and attendance. Evangelical and historically white denominations, such as the SBC, are slowly declining, while Pentecostal, charismatic, and mission-focused groups like the Assemblies of God, LDS Church, and non-denominational charismatic churches are growing rapidly. Historically Black churches such as the NBCUSA remain mostly stable. Globally, Christianity continues to expand, especially in Africa, Asia, and Latin America, even as some Western churches experience decline.