The Apostle Paul defines the gospel with precision as “the gospel of the grace of God” (Acts 20:24). In his epistles he repeatedly insists that this gospel centers on justification by faith alone, apart from the works of the law, and that any addition of human merit, ritual, or ecclesiastical mediation constitutes a different gospel that brings a curse. The Roman Catholic system, as defined by its official dogmas (especially those of the Council of Trent and the Catechism of the Roman Catholic Church), presents a scheme of salvation that is incompatible with the gospel of the grace of God.
Paul’s Explicit Definition of the Gospel of Grace
Paul summarizes the content of the gospel in I Corinthians 15:1–4: Christ died for our sins according to the Scriptures, was buried, and rose again the third day. The instrumental means by which this finished work is received, is by faith alone:
Justification is a declarative act of God that imputes the righteousness of Christ to the believer at the moment of faith. It is not a process of progressive infusion of righteousness contingent upon subsequent works, sacraments, or cooperation with grace. Once justified, the believer is sealed “unto the day of redemption” (Ephesians 4:30)
The Anathema of Galatians Chapter 1
Paul’s language in Galatians 1:6-9 is absolute:
Galatians 1:6-9
6 I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel:
7 Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.
8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
9 As we said before, so say I now again, if any man preach any other gospel unto you than that ye have received, let him be accursed.
Any message that makes human merit, priestly mediation, or continuing works necessary to keep justification is “another gospel.” Paul’s warning applies not only to angels, but also to any church authority that changes the terms of grace.
Roman Catholic Doctrine on Justification and Its Conflict with Paul
The Council of Trent (Session VI, Canon 9) formally anathematizes the gospel of the grace of God: “If anyone says that the sinner is justified by faith alone…let him be anathema.” Roman Catholic teaching says justification is more than being declared right with God; it is an inner change received through the sacraments, beginning with baptism and continued through the Mass, penance, and acts of charity. Faith is necessary, yet insufficient without works and sacramental cooperation. Justification can be increased, diminished, and lost.
This directly contradicts Paul’s insistence that the righteousness by which a man stands accepted before God is the righteousness of Christ received by faith alone (Philippians 3:9; II Corinthians 5:21). The Roman Catholic system reintroduces a form of law-keeping (albeit under the name of “cooperating with grace”) that Paul spent his ministry opposing.
Loss of Salvation by Mortal Sin and Failure of Charity
Yes, official Roman Catholic doctrine explicitly teaches that a justified person can forfeit salvation by committing a mortal sin and that loss of charity is the essence of that forfeiture.
According to the Catechism of the Roman Catholic Church:
The Roman Catholic Church teaches that “charity” (the theological virtue of love of God and neighbor) is the form of all virtues; its absence is definitive of mortal sin. Failure to perform works of charity, when the omission itself constitutes a grave matter done with full knowledge and deliberate consent, can therefore constitute mortal sin and the loss of salvation. The Council of Trent (Session VI, Canon 23) states that one who has been justified can lose the grace of justification by mortal sin and must recover it through the sacrament of penance.
This stands in stark contrast to Paul’s teaching that the believer is “sealed with that holy Spirit of promise, Which is the earnest of our inheritance until the redemption of the purchased possession” (Ephesians 1:13–14) and that “there is therefore now no condemnation to them which are in Christ Jesus” (Romans 8:1).
Paul never conditions the retention of justification upon the avoidance of certain categories of post-conversion sin or upon the continual performance of charitable works. Discipline, loss of reward, and temporal consequences are real (I Corinthians 3:15; 11:30–32), but the eternal standing of those justified in Christ is secure because it rests on Christ’s finished work, not on the believer’s subsequent performance.
When measured against the epistles of Paul, the Roman Catholic system of justification—requiring faith plus works, sacraments as instrumental causes of grace, and the real possibility of losing sanctifying grace through mortal sin or failure of charity—constitutes “another gospel.” It replaces the finished, imputed righteousness received by faith alone with a process of infused righteousness that must be maintained by human cooperation.
Paul’s double anathema in Galatians chapter 1 therefore applies: any teaching that alters the terms of the pure gospel of the grace of God is under a divine curse, regardless of the antiquity or institutional authority that advances it. The only gospel that saves is the one Paul preached: justification by grace alone, through faith alone, in Christ alone, to the glory of God alone.