Dear Protestants: Why Should I Agree with You?

Last updated on: September 20, 2025 at 11:37 pm by Dennis Knapp

0 Comments

Dear Protestants: Why Should I Agree with You? 2025-09-20T23:37:17-06:00 Dennis Knapp

LOGO Patheos Explore the world's faith through different perspectives on religion and spirituality! Patheos has the views of the prevalent religions and spiritualities of the world.

AI image created by author.

As most readers know, I converted from Protestantism to Catholicism. What many may not know is that I once viewed Catholicism as teaching a false gospel and a corruption of authentic Christianity. How did I change from a committed five-point Calvinist and anti-Catholic into a Catholic? In short, I studied the historical evidence—early Church writings and even pagan descriptions of Christians—and concluded that the Church Jesus established in the first century is the Catholic Church.

Why did I start researching Catholic claims? Honestly, I set out to disprove them and to rescue people from what I saw as a deceived organization. I never intended to join the Catholic Church.

Yet my research surprised me. I found truths I never expected and failed to find things I assumed existed.

What I discovered:

Apostolic succession
An authoritative Church
A sacramental Church
The primacy of Rome and the Petrine ministry
A Church teaching that faith and works cooperate through God’s love and grace

What I did not find:

Scripture as the sole authority (sola scriptura)
Faith alone (sola fide)
Forensic justification
Substitutionary atonement (Jesus bearing the wrath of God)
Church governance on strictly Reformed “low church” lines

These discoveries left me with two choices: join the Catholic Church or accept that the historic Church, which claimed Jesus as its founder, went astray almost immediately. That second option raised even more problems. Why should I accept Calvin or Luther, who appeared in the 16th century, and not Joseph Smith in the 19th? If the Church erred from the start, why trust its list of New Testament books? Why believe in doctrines like the Trinity and the Incarnation? If the early Church collapsed so quickly, even Protestant essentials rest on shaky ground.

So, I must ask: Protestants, why should I agree with you?

Gavin Ortlund vs. Joe Heschmeyer

A Protestant friend recently shared a debate between Dr. Gavin Ortlund, a Reformed Baptist, and Joe Heschmeyer, a Catholic apologist, on the papacy.

Here’s the debate:

My friend insisted Ortlund “destroyed” Heschmeyer. Ortlund argued that the early Church never taught papal infallibility as Vatican I defined it in 1870. Since he did not find a Vatican I view of the papacy in first-century writings, he rejected it. When asked about Scripture (Matthew 16:18–19, Luke 22:31–32, John 21:15–17, Acts 15), he dismissed it as a matter of interpretation. By “destroyed,” my friend meant that Heschmeyer failed to meet Ortlund’s impossible standard: historical proof of Vatican I language in the first century. When Heschmeyer showed biblical development toward the papacy, Ortlund dismissed it, wrongly claiming Vatican I disallows development.

What struck me most as a Catholic was Ortlund’s lack of awareness of the consequences of his reasoning. If applied consistently, his standard would also undermine belief in the Incarnation, the Trinity, and even Protestant essentials like sola scriptura and sola fide.

Ortlund’s Criteria Applied More Fairly

Take the Trinity. The final definition came at the Council of Constantinople in 381, long after the New Testament. The Church used terms absent from Scripture—ousia, homoousia—which Arius and his followers denounced as pagan corruption. Like Ortlund, Arius claimed no evidence from the first century supported those words, and he countered every appeal to Scripture with his own interpretation.

What about the solas? We do not see a clear articulation of sola scriptura or sola fide until the 16th century. Some suggest John Hus anticipated them in the 15th century, but I disagree. Measured by Ortlund’s standard, the solas fare far worse than the papacy, which has at least some second-century support. No one—absolutely no one—taught Luther’s and Calvin’s solas before the Reformation. Protestants like Ortlund argue that Scripture itself clearly teaches the solas and therefore the first century did as well. But that claim depends on interpretation. If you dismiss Catholic biblical arguments for the papacy as subjective interpretation, then I can just as easily dismiss your claims about the solas.

Again, Why Should I Agree with You?

If I accept Ortlund’s standard, then I must reject not only the papacy but also the Trinity, the Incarnation, and even the solas themselves, since none of them appear in the 1st century in their final form. If I relax the standard, then I can allow for development—but that same allowance makes room for the Catholic view of the papacy.

So, the real question is not whether the early Church taught Vatican I in the 1st century, but whether Christ gave His Church the authority to grow in clarity without losing the truth He entrusted to it. On that question, the historical evidence points unmistakably to the Catholic Church.

Again, I ask my Protestant friends: why should I agree with you?

If you disagree, I welcome your correction in the comments below.