Where the traditions land

Population figures are each tradition's own most recent published count. Eligibility is set against the World Christian Database, the standard reference for global denominational data.

Why the disagreement

This question splits along more axes than most, because it isn't really asking what a tradition believes — it's asking how each tradition decides what to believe. Catholic and Orthodox teaching agree Scripture can't safely be read outside the Church, but locate that check differently: Catholicism in a specific living office, the bishops in communion with Rome; Eastern and Oriental Orthodoxy in the Church's accumulated life across time — Holy Tradition, the Fathers, the councils — with no single person as the final word.

The Reformation-descended traditions all give Scripture the final say over any church office, but disagree on how much room tradition and reason get alongside it. Lutheran, Reformed, Baptist, Pentecostal, and Adventist teaching hold that Scripture interprets Scripture under the Holy Spirit, with no binding office above it. Anglican and Methodist teaching, descended from a shared root, keep Scripture primary but give tradition and reason real, ongoing weight beside it, not just for reference.

LDS and Jehovah's Witnesses both reject the idea that interpretive authority ended when the biblical canon closed. LDS teaching holds that living prophets and apostles still receive revelation that can clarify or add to it. Jehovah's Witnesses locate that same kind of ongoing authority in one body, the Governing Body, as the sole channel through which correct interpretation is given.

Solving the disagreement

This is the one question in this format where "more argument" can't even get started, because the disagreement is about who gets to judge the argument's outcome. Appealing to a Bible verse to prove that Scripture alone is authoritative already assumes the Reformed/Baptist answer; appealing to a Church council to prove councils carry that authority already assumes the Catholic or Orthodox one. Every route to resolving this question runs through a method whose legitimacy is exactly what's being disputed, which makes it structurally different from a normal disagreement about facts. Two people can share every fact in the Bible and still walk away with opposite answers, because the question was never about the facts — it was about who's authorized to declare which reading of the facts wins, and that's a claim about authority no set of shared facts can arbitrate from outside itself.

Sources

Same standing source per tradition on every post, not hunted per question.

• Catholic — Catechism of the Catholic Church
• Eastern Orthodox — Nicene-Constantinopolitan Creed (binding across all jurisdictions); The Longer Catechism of St. Philaret of Moscow (widely used, not binding on every jurisdiction)
• Oriental Orthodox — Catechism of the Coptic Orthodox Church, Fr. Tadros Y. Malaty (Amazon — no full free text found)
• Anglican — Thirty-Nine Articles of Religion
• Lutheran — Book of Concord
• Reformed/Presbyterian — Westminster Confession of Faith
• Methodist/Wesleyan — Articles of Religion
• Southern Baptist Convention — Baptist Faith & Message 2000
• Pentecostal (Trinitarian) — Assemblies of God Statement of Fundamental Truths
• Seventh-day Adventist — 28 Fundamental Beliefs
• LDS — Book of Mormon and Doctrine and Covenants
• Jehovah's Witnesses — What Does the Bible Really Teach?