Why do Protestants and Catholics differ so sharply on authority, Mary, and the nature of the true church—and why does it matter for following Jesus today?

In this episode, Mark Vance continues the “Why Protestantism?” series by examining some of the most significant theological differences between Roman Catholicism and Protestant belief. With clarity and charity, Mark explains how Catholic teachings on Mary, the papacy, and church authority developed—and why he believes they obscure the clarity of the gospel.

Mark walks through the “four Marian doctrines,” the Catholic understanding of sacred tradition, and the claim of papal infallibility, showing how these teachings shape the Catholic view of the church. He contrasts this with the Protestant conviction that Scripture alone is the final authority and that salvation is grounded solely in the finished work of Christ. This episode lays crucial groundwork for understanding why the Reformers believed a return to biblical authority was necessary for the health of the church.

Episode Highlights

00:00 — Why Protestantism? Continuing the series and framing today's topic: authority
 02:47 — How Catholic doctrine develops: tradition, councils, and magisterial teaching
 06:10 — The four Marian doctrines (Immaculate Conception, Perpetual Virginity, Assumption, and Mary as Mediatrix)
 11:52 — Why these Marian teachings matter for understanding the gospel
 14:30 — How Catholicism understands the church’s teaching authority (magisterium)
 16:44 — The logic behind papal infallibility and ex cathedra teaching
 19:55 — Protestant concerns: where is the biblical warrant for these doctrines?
 22:18 — Scripture vs. tradition: which has final authority?
 24:12 — Why Mark believes the Catholic view of authority obscures gospel clarity

Resources

• Cornerstone Church Sermons: Listen online
• Gavin Ortlund, What It Means to Be Protestant (Truth Unites)
• Matthew Barrett, The Reformation as Renewal
• Michael Svigel, RetroChristianity: Reclaiming the Forgotten Faith
• Chad Van Dixhoorn (ed.), Creeds, Confessions, and Catechisms: A Reader’s Edition
• Catechism of the Catholic Church (Vatican)