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 the same fault line that produced the Reformation's sharpest internal arguments, and the five positions here map closely onto that split. Catholic teaching defines the mechanism precisely: the whole substance of the bread and wine converts into the substance of Christ's body and blood, while everything perceptible — taste, appearance — remains unchanged, built on Aristotelian categories of substance and accident. Eastern and Oriental Orthodox teaching affirms the same real, substantial change happens, using its own term for it, but deliberately refuses to explain the mechanism philosophically, treating it as mystery rather than a metaphysical claim to define.

Lutheran teaching charts a third course: Christ's body and blood are truly, substantially present "in, with, and under" the bread and wine, but the bread and wine themselves don't change into something else — precise enough that confessional Lutherans reject the popular label "consubstantiation" for it: no conversion of substance, just a real union of two substances that both remain.

Anglican, Reformed, and Methodist teaching all explicitly reject transubstantiation by name, in nearly identical wording — Methodist's Article XVIII is a direct copy of Anglican's Article XXVIII — and land in the same place: Christ is really present, but spiritually rather than physically, received through the faith of the person receiving, not through anything happening to the elements themselves.

Southern Baptist, Pentecostal, Adventist, LDS, and Jehovah's Witness teaching deny real presence altogether: bread and cup are symbols, a memorial, nothing more — though practice around that shared claim varies sharply. Jehovah's Witnesses observe it only once a year, and only a small "anointed" class actually eats and drinks; everyone else present observes without partaking.

Solving the disagreement

Catholic and Orthodox teaching aren't actually disagreeing about what happens in the Eucharist — both affirm a real, substantial change. What divides them is whether that change should be defined in precise philosophical terms at all, which is a dispute about theological method, not a factual one a new argument could settle.

The deeper fork, running through Lutheran, Reformed, Anglican, Methodist, and memorial-view teaching, comes down to how literally to take one sentence: Christ's words at the Last Supper, "This is my body." Read as a literal identity statement, it points toward real presence in some form. Read the way "I am the door" or "I am the vine" are read elsewhere in the Gospels — as a figure of speech — it points toward the memorial view. Both readings are grammatically possible; nothing in the sentence itself settles which one Jesus intended.

That exegetical question is tangled up with a second one specific to Lutheran and Reformed teaching: whether Christ's physical body, now ascended, even can be present in multiple locations on earth at once. Lutheran Christology says yes, because Christ's human nature shares in the divine attribute of omnipresence; Reformed Christology says no, a real human body has to be somewhere specific, which is exactly why Reformed teaching locates the presence in the believer's spiritual reception rather than the bread itself. That's a question about what Christ's ascended body actually is, not a text either side has stopped citing — a metaphysical commitment neither side's proof texts can adjudicate alone.

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?