A comprehensive, objective deep-dive research on all Catholic-based churches, sects, and denominations.

As a student of Scripture and a servant of Christ in the post-Reformation tradition, I’ve long been drawn to the question of how various branches of Christianity measure up against the unerring standard of the Authorized King James Version (KJV) Bible. Our church, the First Pentecostal Evangelical Church of Canada, stands firmly in the full gospel tradition—Pentecostal in our embrace of the Holy Spirit’s gifts, yet free from the excesses of prosperity preaching or unverified claims that too often distract from the pure Gospel. We hold to the Statement of Faith outlined on our site, emphasizing salvation by faith alone, the priesthood of all believers, and the Bible as our sole infallible rule of faith and practice. For more on our mission, see our About page.

This series represents years of rigorous investigation—poring over ancient councils, papal encyclicals, and modern reports; cross-referencing with KJV texts; and weighing critiques from evangelical, traditionalist, and secular scholars. It’s not an attack but a call to discernment, inviting all seekers to test every doctrine against the Word (1 Thess. 5:21 KJV). In an age of ecumenical compromise and progressive shifts, we must ask: How have these groups drifted from scriptural authority? Our focus is on Catholic-based bodies, from the Vatican core to its offshoots, evaluating deviations in soteriology, ecclesiology, Mariology, moral teachings, and ecumenism/globalism.

This is the gateway to a multi-page exploration, structured for clarity and depth. Each page stands alone yet builds on the last, with hyperlinks for seamless navigation. We’ve drawn from diverse sources—Vatican yearbooks, Pew Research, World Christian Database, academic journals like Theological Studies, and evangelical critiques from scholars like James White and Norman Geisler—to ensure balance. All claims are substantiated; quotes and counterarguments are presented without bias.

Page Navigation

• 1. Overview and Classification
• 2. Global Statistics (2025 Estimates)
• 3. Internal Divisions and Vatican Relations
• 4. Analysis of Deviation from Scriptural Authority (KJV)
• 5. Summary Matrix and Conclusions

By Lord and Right  Rev.  John McIlwraith,  A Bishop of the First Pentecostal Evangelical Church of Canada (FPECC.CA), and Ainsworth Korg, PhD in Theological Studies, Research Assistant.

1. Overview and Classification

Catholic-based churches trace their roots to the early Christian communities but diverged through schisms over doctrine, authority, and practice. The core is Roman Catholicism, claiming unbroken apostolic succession from St. Peter. Eastern Catholicism emerged from unions with Eastern Orthodox rites, retaining Byzantine liturgies while affirming papal primacy. Post-1870 schisms, like Old Catholicism, rejected Vatican I’s papal infallibility. Traditionalist groups, such as the Society of St. Pius X (SSPX), arose after Vatican II (1962-1965), decrying liturgical and ecumenical reforms. Sedevacantists declare the papal see vacant since Vatican II, viewing post-conciliar popes as heretics. Liberal and independent jurisdictions further splintered, often embracing progressive or esoteric elements.

These groups span full communion with the Vatican to outright rejection. Roman and Eastern Catholics maintain unity under the Pope. SSPX operates in irregular status—priests lack faculties but sacraments are valid per Vatican recognition. Old Catholics, via the Union of Utrecht, severed ties in 1889. Sedevacantists and independents form autonomous networks, sometimes consecrating bishops without Vatican approval.

Schisms often stem from authority disputes: papal primacy vs. conciliarism, or sola scriptura vs. tradition/magisterium. Historical context reveals patterns—early Eastern rifts over theology (e.g., Chalcedon 451), medieval Western over politics (Avignon 1378-1417), Reformation over soteriology (1517). Vatican II accelerated fragmentation, with progressives decrying “rigidity” and traditionalists “modernism.” Wikipedia: Catholic Church by Country notes 1.4 billion adherents claim Catholic identity, but schisms fragment this. Evangelical critiques, like James White’s The Roman Catholic Controversy, argue these splits expose sola scriptura’s necessity, as unchecked tradition breeds error.

Yet, as 1 Corinthians 1:10 KJV urges, “that ye all speak the same thing, and that there be no divisions among you,” we see unity’s ideal shattered. Counterarguments from Catholic sources, like the Vatican’s Unitatis Redintegratio, frame schisms as wounds needing healing through dialogue. This overview sets the stage; next, we examine numbers.

Continue to Page 2: Global Statistics