The doctrine of "once saved, always saved" (OSAS), also known in some circles as eternal security or the perseverance of the saints, is a hallmark of certain Protestant traditions, particularly Calvinism. It posits that once a person genuinely accepts Jesus Christ as Savior—often through a one-time "born again" experience—their salvation is eternally secure, regardless of future sins, apostasy, or lack of perseverance. From a Catholic perspective, this view is erroneous, incomplete, and misleading, as it overlooks Scripture's portrayal of salvation as an ongoing process requiring free will, continual repentance, and fidelity to God's grace. Catholics affirm that salvation can be lost through unrepented mortal sin or deliberate rejection of Christ, emphasizing the need for lifelong perseverance.
Catholics view salvation through a "both/and" lens: it is a past gift (e.g., justification by grace through faith at baptism, as in Ephesians 2:8–9: "For by grace you have been saved through faith"), an ongoing reality (Philippians 2:12: "work out your own salvation with fear and trembling"), and a future hope (Romans 13:11: "salvation is nearer to us now than when we first believed"; see also 1 Corinthians 3:15 and 5:5). This contrasts with OSAS's emphasis on a singular, irrevocable moment of conversion. The Bible repeatedly warns believers against complacency, implying the possibility of forfeiture: for instance, 1 Corinthians 15:1–2 states that the gospel "in which you stand, by which you are saved, if you hold it fast—unless you believed in vain." Early Church writings, like the Didache (c. A.D. 70), echo this: "the whole time of your faith will not profit you, if you be not made complete in the last time."
While no external force can snatch believers from God's hand (John 10:28; Romans 8:38–39), individuals retain free will to reject grace through sin. Romans 8:38–39 lists cosmic powers, persecution, and death as unable to separate us from God's love—but notably omits personal sin, which Paul addresses elsewhere as a self-inflicted severance (Galatians 5:4: "You are severed from Christ... you have fallen away from grace"). Jesus warns in John 15:6 that branches (believers) who do not "remain" in Him are "thrown away... and withered; and the men gather them and cast them into the fire, and they are burned." Similarly, Paul fears personal disqualification despite his apostleship (1 Corinthians 9:27: "I pummel my body and subdue it, lest after preaching to others I myself should be disqualified"). These passages underscore that "remaining in Christ" is an active, ongoing choice, not an automatic state.
OSAS ignores Scripture's calls to vigilance (e.g., 2 Timothy 4:7: "I have fought the good fight, I have finished the race, I have kept the faith") and the reality of free will. Salvation is God's gracious initiative, but it demands our lifelong response—through faith working in love (Galatians 5:6). For those tempted by sin, this fosters hope in mercy rather than false assurance, urging continual conversion and perseverance in Christian discipleship until the end.