A Guide for the 1689 Reformed Baptist

Understanding Some of
Rome’s Errors

This guide equips confessional Reformed Baptists to engage Roman Catholics with accuracy, charity, and biblical conviction. Every Roman Catholic you meet bears the image of God and needs the same Gospel you have received. Know what Rome actually teaches so you can show, from Scripture, where she has gone astray.

Scroll to begin

Before You Begin

Foundational Approach

A library of old theological books
Represent Rome’s Position So Accurately That They Recognize It Themselves

We distinguish “Rome” (the Roman Catholic Church) from universal catholicity (the true Church throughout all ages). The goal is not to caricature but to understand, and not merely to understand but to lovingly confront error with the truth of the Gospel.

Do

Listen first. Ask Roman Catholics what they believe rather than assuming. Many are functionally ignorant of what their church officially teaches.

Use their sources. When discussing Marian dogmas, cite the Catechism. When discussing justification, cite Trent. This shows you understand their position.

Distinguish Rome from individual Catholics. The institution teaches these things; individuals may be more or less informed.

Explain the dulia/latria distinction fairly before showing from Scripture why it fails.

Don’t

Don’t mock or ridicule. Roman Catholics sincerely believe they are honoring Christ through honoring Mary.

Don’t misrepresent. Don’t say Rome teaches Mary is divine or equal to Christ—they teach she is the highest creature.

Don’t assume all Catholics know their theology. Many are unaware of Trent or the technical distinctions.

Don’t start with secondary issues. Start with Christ and the Gospel, not Mary or the saints.

Part 1

What Rome Teaches
About Mary

Rome has developed an elaborate Marian theology built on four defined dogmas and several additional doctrines. Each dogma builds on the others, forming an interconnected theological structure that elevates Mary far beyond what Scripture warrants.

The Immaculate Conception (1854)

This dogma does not refer to the virgin birth of Christ (a common misconception) but to Mary’s own conception. Pope Pius IX defined it in Ineffabilis Deus (1854): Mary was, from the first moment of her conception, by a singular grace and privilege of Almighty God and in view of the merits of Jesus Christ, preserved immune from all stain of original sin.

CCC 491 states that the Church became ever more aware that Mary, “full of grace” through God, was redeemed from the moment of her conception. CCC 492 teaches that this unique holiness comes wholly from Christ—Mary is “redeemed, in a more exalted fashion, by reason of the merits of her Son.”

— Catechism of the Catholic Church, 490–493

Rome calls this preservative redemption: rather than being rescued from sin after falling into it, Mary was prevented from ever contracting it—like someone kept from falling into a pit rather than pulled out of one. CCC 493 adds that by God’s grace, Mary remained free of every personal sin her whole life long.

Rome’s scriptural arguments center on Luke 1:28, where the angel greets Mary as kecharitomene (“full of grace”). Rome argues the perfect passive participle indicates a completed state of grace prior to the Annunciation. Genesis 3:15 is read as the protoevangelium, with Mary as the “New Eve” in perpetual enmity with the serpent. Rome also appeals to the Eve–Mary typology from early Church Fathers like Irenaeus and Justin Martyr: as Eve cooperated in the Fall, Mary cooperated in redemption—“death through Eve, life through Mary.”

The Perpetual Virginity

Rome teaches Mary’s virginity in three dimensions: virginitas ante partum (before birth), virginitas in partu (during birth—Christ’s birth did not diminish Mary’s virginal integrity but sanctified it), and virginitas post partum (after birth—Mary remained a virgin for the rest of her life).

CCC 499 confesses Mary’s “real and perpetual virginity even in the act of giving birth.” The liturgy celebrates her as Aeiparthenos—the “Ever-Virgin.”

— CCC 499; cf. Second Council of Constantinople (553)

The Council of Trent used a striking analogy: Christ came forth “as rays of the sun penetrate the substance of glass without breaking or injuring it.” CCC 500 addresses the “brothers of Jesus” objection, claiming they were cousins (following Jerome) or step-brothers from Joseph’s prior marriage (following the Protoevangelium of James).

The Assumption (1950)

Pope Pius XII defined this dogma in Munificentissimus Deus (1950)—the first and only ex cathedra papal pronouncement since Vatican I defined papal infallibility.

“The Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory.”

— Munificentissimus Deus (1950); CCC 966

Rome’s scriptural case is thematic rather than based on direct proof-texts. Genesis 3:15 is invoked to argue complete victory over the serpent implies victory over death. Revelation 12:1 is traditionally interpreted as Mary in her glorified state. Even Roman Catholic apologists concede that no express scriptural proofs are available—the doctrine rests primarily on tradition, theological reasoning, and the sensus fidelium.

Mary as Mediatrix

Mary’s maternal function “in no way obscures or diminishes this unique mediation of Christ, but rather shows its power.” Her salutary influence “flows forth from the superabundance of the merits of Christ, rests on his mediation, depends entirely on it and draws all its power from it.”

— Lumen Gentium 60 (Vatican II, 1964)

Lumen Gentium 62 declares that Mary “did not lay aside this saving office but by her manifold intercession continues to bring us the gifts of eternal salvation.” She is invoked under the titles of Advocate, Helper, Benefactress, and Mediatrix. CCC 970 offers the key analogy: just as Christ’s priesthood is shared by ministers, His “unique mediation does not exclude but rather gives rise to a manifold cooperation.”

The title “Co-Redemptrix” has been used by some popes but was never defined as dogma. In November 2025, the Dicastery for the Doctrine of the Faith declared it “always inappropriate” to use this title, as it risks eclipsing Christ’s exclusive role in redemption.

Queen of Heaven

Pope Pius XII formally proclaimed Mary’s queenship in Ad Caeli Reginam (1954). Rome grounds this in her divine motherhood (since she bore a Son who was King, she is therefore Queen—citing the Old Testament Gebirah tradition where the queen was the king’s mother; cf. 1 Kings 2:19) and her unique cooperation in redemption as the New Eve. CCC 966 states Mary was “exalted by the Lord as Queen over all things.”

Part 2

Worship, Veneration, &
the Line Rome Draws

Hands folded in prayer with dramatic light
Understanding the Distinction — And Where It Breaks Down

Latria (Λατρεία)

Supreme worship reserved for God alone. Aquinas: “the worship which is due to the Divinity.” Includes adoration, sacrifice, and absolute submission due only to the Triune God (CCC 2113). To give latria to a creature is idolatry.

Dulia (Δουλεία)

Honor paid to saints and angels as servants of God. Aquinas: “dulia pays due service to a human lord”—a genuinely distinct virtue from latria, different in kind, not merely degree. Given to those who “excelled in virtue.”

Hyperdulia (Υπερδουλεία)

Special honor due to Mary alone. Aquinas: “the worship of latria is not due to her, but only that of dulia: but in a higher degree… inasmuch as she is the Mother of God.” Lumen Gentium 66 says this “differs essentially from the cult of adoration.”

Rome’s defense rests on three pillars: sacrifice is never offered to saints, the difference between dulia and latria is essential and qualitative, and invoking saints is understood as requesting intercession. The Second Council of Nicaea (787) distinguished between timētikē proskynēsis (honorary veneration) and alēthinē latreia (true adoration). The Communion of Saints doctrine (CCC 954–962) grounds the practice: the union between pilgrims on earth and the blessed in heaven “is in no way interrupted, but on the contrary is reinforced by an exchange of spiritual goods.”

Where the Line Blurs in Practice

⚠ Devotional Practices That Raise Serious Questions

The Salve Regina addresses Mary as “our life, our sweetness, and our hope”—language Scripture reserves for God or Christ (Col. 3:4; 1 Tim. 1:1). The Memorare declares that “never was it known that anyone who fled to thy protection… was left unaided”—attributing unfailing efficacy to Mary’s intercession. St. Louis de Montfort’s Act of Consecration includes: “I deliver and consecrate to thee, as thy slave, my body and soul.”

These prayers presuppose that Mary can hear and respond to millions of simultaneous petitions worldwide—an attribute that implies something approaching omniscience.

Notably, Vatican II itself acknowledged the danger: Lumen Gentium 67 admonishes theologians “to abstain zealously both from all gross exaggerations as well as from petty narrow-mindedness.” This suggests Rome recognizes that popular practice can cross the line her theology carefully draws.

From a Reformed and biblical perspective, the practices associated with hyperdulia and dulia constitute worship of creatures regardless of how Rome categorizes them. The issue is not merely Rome’s intention but the nature of the acts themselves. Praying to a creature, consecrating oneself to a creature, and attributing divine-sounding titles to a creature are acts that Scripture directs exclusively toward God.

Part 3

How Rome Understands
Christ’s Death

Rome’s doctrine of the atonement differs from the Reformed position in subtle but consequential ways. Understanding these differences is essential because they drive the entire Roman Catholic sacramental system—the Mass, purgatory, indulgences, and the treasury of merit all flow from Rome’s particular view of what Christ accomplished on the cross.

A cross silhouetted against dramatic light at dawn
Satisfaction of Honor or Payment of Penalty?

Rome broadly follows the satisfaction theory of Anselm of Canterbury (as modified by Aquinas) rather than penal substitutionary atonement. The key distinction: Anselm understood sin primarily as defrauding God of the honor He is due. Christ’s death, as the ultimate act of obedience by one who did not owe death, brings God infinite honor and thereby “satisfies” the debt. As Anselm wrote: “The honour taken away must be repaid, or punishment must follow” (Cur Deus Homo). Christ provides satisfaction so that punishment can be averted.

Rome: Satisfaction

Christ offered satisfaction to restore God’s honor through supererogatory merit. The focus is on compensation/restitution. Christ’s death was “supererogatory” (above what was required) and thus merited reward applied to sinners. This grace is stored in the “Treasury of Merit” and distributed through the sacraments.

Reformed: Penal Substitution

Christ bore the actual punishment (penalty) due to sinners. God’s wrath was propitiated by Christ receiving punishment in the sinner’s place. Christ was “made sin” (2 Cor. 5:21) and bore the curse (Gal. 3:13). If Christ bore the full penalty, nothing remains to pay.

Rome generally denies that the Father poured out His wrath on the Son as punishment. They view the Cross more as a supreme act of love and obedience that outweighs Adam’s disobedience, rather than a legal execution where Christ was “cursed” by God in the sinner’s place. This distinction matters enormously: if Christ bore the full legal penalty, nothing remains for the sinner to pay. If He merely made satisfaction for a debt of honor, temporal consequences may still require purification.

The Mass as Re-Presentation of Calvary

“The Eucharist is a sacrifice because it re-presents (makes present) the sacrifice of the cross, because it is its memorial and because it applies its fruit.”

— CCC 1366

Trent (Session 22) declared that in the Mass, “that same Christ is contained and immolated in an unbloody manner.” The Mass is declared to be “truly propitiatory” (CCC 1367). It actually accomplishes propitiation and applies the fruits of Calvary, including forgiveness of sins. This depends on transubstantiation—the teaching that the substance of bread and wine is converted into Christ’s actual body and blood (Trent, Session 13).

Purgatory and Temporal Punishment

Rome teaches that sin has a double consequence: grave sin incurs eternal punishment, while every sin also entails temporal punishment—disordered attachment requiring purification. CCC 1472–1473 explains that forgiveness remits eternal punishment, but temporal punishment may remain. Those who die imperfectly purified “undergo purification, so as to achieve the holiness necessary to enter the joy of heaven” (CCC 1030).

The treasury of merit (CCC 1476–1477) is the mechanism by which the Church draws upon Christ’s infinite merits—supplemented by the merits of Mary and the saints—to remit temporal punishment through indulgences. Pope Clement VI defined this treasury in Unigenitus Dei Filius (1343).

⚠ The Practical Stakes

This entire system—purgatory, indulgences, the treasury of merit, the Mass as propitiatory sacrifice—stands or falls on Rome’s atonement theology. If Christ bore the full penalty for sin, there is no remaining temporal punishment to purge. The hope of the Roman Catholic in the pew is placed not in the finished work of Christ alone but in a complex sacramental system administered by the institutional church.

Part 4

Rome’s Doctrine
of Justification

The doctrine of justification is where the difference between Rome and the Reformation becomes sharpest. R.C. Sproul called this “the article upon which the church stands or falls.” Two words capture the divide: infusion versus imputation.

Scales of justice
Transformation or Declaration? Infusion or Imputation?

The Council of Trent (Session 6, 1547) defined justification as “not only a remission of sins but also the sanctification and renewal of the inward man” (Chapter 7; cf. CCC 1989). This is the critical difference: Rome teaches justification is not merely God declaring someone righteous but God actually making them righteous through an internal transformation.

Trent’s Chapter 7 lays out the causes with scholastic precision: the final cause is God’s glory; the efficient cause is God who washes and sanctifies; the meritorious cause is Christ’s passion; the instrumental cause is the sacrament of baptism; and the formal cause is:

“The justice of God, not that by which He Himself is just, but that by which He makes us just, that, namely, with which we being endowed by Him, are renewed in the spirit of our mind, and not only are we reputed but we are truly called and are just, receiving justice within us.”

— Council of Trent, Session VI, Chapter 7

That phrase—“not only are we reputed but we are truly called and are just”—is a direct rejection of the Protestant doctrine of imputation.

Infused Righteousness Explained

At justification God infuses sanctifying grace (gratia sanctificans) into the soul. This grace is a real, created quality inhering in the soul that makes the person genuinely, internally righteous. Together with remission of sins, the justified person receives faith, hope, and charity infused simultaneously. Grace in Rome’s system is not merely favor but a substance-like gift that transforms the soul.

Trent Canon 11 anathematizes anyone who says “men are justified either by the sole imputation of the justice of Christ or by the sole remission of sins, to the exclusion of the grace and the charity which is poured forth in their hearts by the Holy Ghost.”

— Council of Trent, Session VI, Canon 11

Rome insists the righteousness is genuinely ours (it inheres in us) while simultaneously being God’s (because God infused it). This is fides caritate formata—“faith formed by love/charity.” Without charity, faith is fides informis (“dead faith”)—real but insufficient. Trent Chapter 7: “Faith, unless hope and charity be added to it, neither unites man perfectly with Christ nor makes him a living member of His body.”

A Process That Can Be Lost

Because justification involves actual internal transformation rather than a legal declaration, Rome teaches it is a process with stages: prevenient grace calls and awakens; faith comes by hearing; fear, hope, and love follow; repentance prepares; and baptism confers justification itself. After initial justification, the justified person grows: “They increase in that justice received through the grace of Christ and are further justified” (Trent, Chapter 10).

Critically, justification can be lost through mortal sin (Trent, Chapter 15): “The grace of justification once received is lost not only by infidelity… but also by every other mortal sin.” When lost, it must be recovered through the sacrament of Penance—what Trent calls “the second plank after the shipwreck of grace lost” (Chapter 14).

Merit & Rome’s Condemnation of Sola Fide

While no one can merit initial justification (CCC 2010), after justification the believer can truly merit an increase of grace, eternal life, and heavenly glory (Trent, Canon 32). Rome distinguishes condign merit (meritum de condigno)—genuine merit from grace-empowered works—from congruent merit (meritum de congruo)—a lesser fittingness without strict obligation.

⚠ The Anathema Against Sola Fide

Trent, Session 6, Canon 9: “If anyone says that the sinner is justified by faith alone, meaning that nothing else is required to cooperate in order to obtain the grace of justification, and that it is not in any way necessary that he be prepared and disposed by the action of his own will, let him be anathema.” Canon 12 similarly condemns the idea that justifying faith is merely “confidence in divine mercy which remits sins for Christ’s sake.” These anathemas remain in force today.

Part 5

The Reformed Baptist
Response from Scripture

Having presented Rome’s positions fairly from her own sources, we now turn to the biblical and confessional response. The Reformed critique rests on the five solas: sola Scriptura, solus Christus, sola gratia, sola fide, and soli Deo gloria. Each of Rome’s distinctive doctrines undermines one or more of these principles.

Scripture Against the Marian Dogmas

Against the Immaculate Conception: Romans 3:23 declares “all have sinned.” Romans 5:12 teaches sin “spread to all men because all sinned.” Paul makes universal statements with no exception for Mary. Most tellingly:

My spirit rejoices in God my Savior. — Luke 1:47

If Mary were sinless, she would not need a Savior. Rome’s “preservative redemption” is an ad hoc distinction absent from the text.

John Calvin (on Luke 1:47)

“Mary confesses that she was preserved by the free mercy of God… She places herself in the rank of sinners, and implores pardon… The Papists are refuted who imagine that Mary was free from all sin.”

Francis Turretin

“Mary was not conceived immaculately… She needed the redemption of Christ as much as other sinners.”

Against the Perpetual Virginity: Matthew 1:25 states Joseph “knew her not until she had brought forth her firstborn son”—the Greek heōs most naturally implies a change in state afterward. Matthew 13:55–56 names Jesus’ brothers and mentions sisters. Galatians 1:19 calls James “the Lord’s brother” using adelphos, the standard Greek term for a biological sibling. The NT has a separate word for cousin (anepsios, Col. 4:10) and relative (suggenēs, Luke 1:36).

John Calvin (on Matthew 1:25)

The word “until” implies normal marital relations afterward.

John Calvin (on Matthew 13:55)

“We must conclude that Mary brought forth other children after Christ.”

Against the Assumption: No scriptural evidence exists whatsoever—a fact even Roman Catholic apologists concede. No mention in any NT book, apostolic letter, or reliable early church document. The doctrine was not defined until 1950. For those holding to sola Scriptura, the absence of any biblical warrant is decisive.

Against Mary as Mediatrix:

There is one God, and there is one mediator between God and men, the man Christ Jesus. — 1 Timothy 2:5
He is able to save to the uttermost those who draw near to God through him, since he always lives to make intercession for them. — Hebrews 7:25

“This office of mediator between God and man is proper only to Christ, who is the prophet, priest, and king of the church of God; and may not be either in whole, or any part thereof, transferred from Him to any other.”

— 1689 LBCF 8.9
William Ames

“The invocation of saints is contrary to Scripture because it attributes to them what belongs to God alone—omniscience (to hear many prayers at once) and omnipotence (to help in all cases).”

Against prayers to saints: Isaiah 8:19 asks: “Should not a people inquire of their God? Should they inquire of the dead on behalf of the living?” Deuteronomy 18:10–11 categorically forbids inquiry of the dead. No biblical example exists of any prayer addressed to a deceased saint, angel, or Mary. Every instance of prayer in the NT is addressed to God.

The Finished Atonement Destroys the Mass

The book of Hebrews demolishes the theological foundation of the Mass with repeated, emphatic declarations of the once-for-all finality of Christ’s sacrifice:

Heb 7:27

He has no need to offer sacrifices daily, “since he did this once for all when he offered up himself.”

Heb 9:12

He entered “once for all into the holy places… by means of his own blood, thus securing an eternal redemption.”

Heb 9:25–28

“He has appeared once for all at the end of the ages to put away sin by the sacrifice of himself.”

Heb 10:10–14

“By a single offering he has perfected for all time those who are being sanctified.”

John 19:30

“It is finished” (tetelestai—perfect tense: completed, with continuing results).

Heb 1:3

After making purification for sins, Christ “sat down at the right hand of the Majesty on high.”

Why He Sat Down

OT priests never sat down—they stood daily because their work was never done (Heb. 10:11). Christ sat down because His atoning work is complete. A sacrifice that must be perpetually “re-presented” contradicts the entire argument of Hebrews.

John Calvin (Institutes 2.16.2)

“He bore the weight of divine severity… He suffered in the flesh… that by enduring the punishment due to us, he might obtain pardon for us.”

John Owen (The Death of Death)

“I affirm that Christ paid idem, that is, the same thing that was in the obligation, and not tantumdem, something equivalent… the law was relaxed in respect of the person suffering, but executed in respect of the penalty suffered.”

Francis Turretin

“Nothing was wanting for a full and true satisfaction… Not the essence and kind of punishment because the death denounced by the law was endured by him.”

Charles Hodge

“The Scriptures teach that Christ bore our sins, that he was made a curse for us, that he was made sin for us… This can only mean that he bore the penalty of the law.”

Purgatory Contradicts Immediate Presence with Christ

Luke 23:43

“Today you will be with me in paradise”—not “today you will enter purgatory.”

2 Cor 5:8

“Away from the body and at home with the Lord.”

Phil 1:23

“To depart and be with Christ, for that is far better.”

Heb 9:27

“It is appointed for man to die once, and after that comes judgment”—no intermediate state.

Rom 8:1

“There is therefore now no condemnation for those who are in Christ Jesus.”

If the thief on the cross went straight to paradise with no sacraments, penance, or works, purgatory is unnecessary. If Paul expected purifying fire after death, departing to suffer it would hardly be “far better.” Rome’s chief proof-text (2 Maccabees 12:41–46) comes from a book not included in the Hebrew canon and not accepted as Scripture by Protestants.

Sola Fide & the Imputed Righteousness of Christ

“Those whom God effectually calls, he also freely justifies, not by infusing righteousness into them, but by pardoning their sins, and by accounting and accepting their persons as righteous; not for anything wrought in them, or done by them, but for Christ’s sake alone; not by imputing faith itself, the act of believing, or any other evangelical obedience to them, as their righteousness; but by imputing Christ’s active obedience unto the whole law, and passive obedience in his death for their whole and sole righteousness by faith, which faith they have not of themselves; it is the gift of God.”

— 1689 LBCF 11.1

Every phrase is a deliberate rejection of Rome. “Not by infusing”—contra Trent’s formal cause. “By accounting and accepting”—forensic declaration, not ontological transformation. “Not for anything wrought in them”—contra merit. “By imputing Christ’s active obedience… and passive obedience”—the double imputation that is the glory of the Gospel.

“Christ, by his obedience and death, did fully discharge the debt of all those who are justified; and did, by the sacrifice of himself in the blood of his cross, undergoing in their stead the penalty due to them, make a proper, real, and full satisfaction to God’s justice in their behalf.”

— 1689 LBCF 11.3

The great exchange: our sin is imputed to Christ—He bears its penalty. His perfect righteousness is imputed to us—we are declared just. This is what Luther called iustitia aliena—an alien righteousness from outside ourselves.

Francis Turretin

“Justification is a judicial and forensic act… not an infusion of righteousness, but an imputation of it.”

John Owen (Justification)

“The righteousness by which we are justified is not our own, inherent in us, but the righteousness of Christ imputed to us.”

John Calvin (Institutes 3.11.4)

“As if the righteousness of Christ were not a true righteousness, unless it be inherent in us! As if our righteousness were not distinguished from the righteousness of Christ by this very thing—that ours is a quality infused into us, but his is the merit which he has acquired!”

Francis Turretin (on Imputation)

“What is inherent is opposed to what is imputed… Christ was made sin for us, not inherently or subjectively (because he knew no sin), but imputatively (because God imputed to him our sins)… Therefore, we also are made righteousness, not by infusion, but by imputation.”

The key Scriptures for sola fide form an unbreakable chain:

Rom 3:28

“One is justified by faith apart from works of the law.”

Rom 4:4–5

“To the one who does not work but believes in him who justifies the ungodly, his faith is counted as righteousness.”

Rom 5:1

“Since we have been justified by faith, we have peace with God.”

Gal 2:16

“A person is not justified by works of the law but through faith in Jesus Christ.”

Eph 2:8–9

“By grace you have been saved through faith… not a result of works.”

Titus 3:5

“He saved us, not because of works done by us in righteousness, but according to his own mercy.”

What About James 2:24?

Rome appeals to James 2:24 (“a person is justified by works and not by faith alone”) as proof that sola fide is unbiblical. This was Trent’s key proof-text. The Reformed response: Paul and James address different problems. Paul confronts those trusting in works for acceptance before God. James confronts those claiming faith while showing no fruit. James uses “justify” (dikaioo) in an evidential sense—proving faith genuine before people—while Paul uses it in a forensic sense—God declaring the sinner righteous.

The Reformers’ Principle

“Faith alone justifies, but the faith that justifies is never alone.” The 1689 Confession captures this: “Faith thus receiving and resting on Christ and his righteousness, is the alone instrument of justification; yet is not alone in the person justified, but is ever accompanied with all other saving graces, and is no dead faith, but works by love” (LBCF 11.2).

Assurance of Salvation

Rome denies that believers can have infallible certainty of their final salvation. Trent anathematizes anyone who claims such certainty. This is a direct consequence of Rome’s doctrine of infused righteousness: if your standing depends on an internal state that can be lost through mortal sin, how can you ever be certain?

“Temporary believers and others… may… be certainly assured that they are in the state of grace… This certainty is not a bare conjectural and probable persuasion… but an infallible assurance of faith.”

— 1689 LBCF 18.1
The Spirit himself bears witness with our spirit that we are children of God. — Romans 8:15–16
I write these things to you who believe in the name of the Son of God, that you may know that you have eternal life. — 1 John 5:13
I give them eternal life, and they will never perish, and no one will snatch them out of my hand. — John 10:28
John Calvin (Institutes 3.2.16)

“The testimony of the Spirit is… the first and primary ground of assurance… By this testimony we are assured that we are children of God.”

William Perkins

“A Christian may be certain of his salvation… by the witness of the Holy Spirit with his spirit.”

Francis Turretin

“The elect believer… can and ought to be certain of his election and salvation.”

Standing on Their Shoulders

The Theologians Who
Have Gone Before You

An open Bible in warm golden light
A Rich Tradition of Reformed Scholarship

John Calvin called justification “the main hinge on which religion turns” and devoted eight chapters of the Institutes to defending imputed righteousness. He warned that Rome’s teaching, which keeps believers “perpetually in suspense and uncertainty,” is “a most pestilential error.”

John Owen provided one of the most rigorous Puritan defenses, arguing that Rome’s infused righteousness “is not, it cannot be” justification at all: “Whatever an infusion of inherent grace may be… justification it is not—the word nowhere signifying any such thing.”

Francis Turretin, whom Sproul called one of the three most brilliant theologians in history, systematically dismantled Rome’s positions in his Institutes of Elenctic Theology—denying the doctrine of merit, affirming the certainty of justification, and arguing that faith’s form is trust in Christ, not charity.

R.C. Sproul spent his career defending sola fide. His key insight: Rome’s analytical justification (God declares just what He finds to be just) versus the Reformation’s synthetic justification (God declares just on the basis of an alien righteousness) reveals why Rome must deny assurance and why Protestantism can affirm it.

Charles Spurgeon preached: “Justification is the work of a second. The sinner looks to Christ, it is all done—his sin is gone in a moment. The righteousness of Christ is, as in an instant, imputed to the believing sinner.”

James White has argued that Rome’s ultimate appeal is not to Scripture or tradition but to its own self-attested authority—what he calls “Sola Ecclesia.” Sam Waldron’s A Modern Exposition of the 1689 and James Renihan’s To the Judicious and Impartial Reader provide essential commentary for Reformed Baptists.

For Evangelism

Key Gospel Questions
& Core Presentation

These four questions cut to the heart of the differences:

“What is the difference between the honor you give Mary and the worship you give God?” — Helps them articulate dulia/latria, which you can then examine biblically.

“How do you know you have eternal life?” — Rome denies infallible assurance; the Gospel offers certainty through Christ.

“What did Jesus accomplish on the cross?” — Listen for “satisfaction” vs. “penal substitution.”

“Why do you pray to Mary?” — Then ask: “Doesn’t 1 Timothy 2:5 say there is one mediator?”

The Core Gospel Presentation

The Problem

All have sinned and fall short of God’s glory (Rom. 3:23). This includes Mary. The wages of sin is death (Rom. 6:23).

The Solution

God sent His Son, born of a woman (Gal. 4:4), to be the Savior of sinners. Jesus lived the life we couldn’t live and died the death we deserved. He bore God’s wrath in our place (Rom. 3:25; 1 Pet. 2:24).

The Means

We are justified by faith alone in Christ alone (Rom. 3:28; 5:1)—not faith formed by love, not faith plus works, not faith plus sacraments.

The Result

Those who believe have eternal life (John 3:16; 1 John 5:13). They are justified by the imputed righteousness of Christ, not infused righteousness (2 Cor. 5:21).

The Call

Repent of your sins and trust in Christ alone. Turn from reliance on Mary, the saints, your own works, and the sacraments as grounds of your justification, and rest entirely on the finished work of Christ.

Expert Tip: Focus on “Finished”

Ask: “If Christ’s sacrifice was sufficient to satisfy God’s justice, why is the ‘Sacrifice of the Mass’ and the ‘Sacrament of Penance’ still necessary to deal with your sins?”

Practical Wisdom

How to Use This Guide
in Conversation

Most Roman Catholics have never read the Council of Trent, the CCC, or any of the documents cited here. Your goal is not to win an argument but to present the Gospel clearly and let Scripture do its work.

Start with the Gospel itself, not secondary issues. The doctrine of justification is the hinge. Ask: “How do you know you are right with God? What is the basis of your confidence before Him?” Rome’s answer leaves the believer in perpetual uncertainty. The biblical answer offers what Calvin called “rest and tranquility with spiritual joy.”

Use Rome’s own sources. Many Catholics believe they are saved by grace and are unaware that Trent anathematized justification by faith alone. Show them Canon 9 and Canon 11. Then show them Romans 4:4–5. Let them see the contradiction.

On Mary, be respectful but direct. Acknowledge what Scripture does teach—Mary was blessed among women, chosen for an extraordinary role, faithful in her response (Luke 1:38, 48). Then show what Scripture does not teach. Point to Luke 1:47 as the simplest refutation of the Immaculate Conception.

On the Mass, open Hebrews. The argument of Hebrews 7–10 is sustained, cumulative, and devastating to any notion of an ongoing propitiatory sacrifice. Let the text speak.

Above all, remember that the same sovereign grace that opened your eyes to the Gospel can open the eyes of your Roman Catholic neighbor. You are not the Savior—you are the messenger.

Conclusion

Christ Alone

The differences between 1689 Reformed Baptist theology and Roman Catholicism are not peripheral—they cut to the heart of how a sinner stands righteous before a holy God. Rome offers an elaborate sacramental system of infused grace, cooperative merit, ongoing sacrifice, Marian mediation, and post-mortem purification. Scripture offers Christ alone—His finished work on the cross, His perfect righteousness imputed to sinners, received by faith alone, through grace alone, to the glory of God alone.

The most loving thing you can do for a Roman Catholic is tell them the truth: that the “proper, real, and full satisfaction” for sin has already been made by Christ (1689 LBCF 11:3), that their standing before God depends not on what has been infused into them but on what has been credited to their account, and that they may have—right now, this moment—the peace with God that comes through justification by faith (Romans 5:1).

We contribute nothing to our salvation except the sin that made it necessary. The righteousness that saves us is entirely alien—it belongs to Another, and it is given freely to all who believe.

For there is one God, and there is one mediator between God and men, the man Christ Jesus, who gave himself as a ransom for all. — 1 Timothy 2:5–6
For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast. — Ephesians 2:8–9

SOLI DEO GLORIA