Here's a historical overview of the doctrine, tracing its origins and development:

I. Pre-Reformation Era (Before 16th Century)

• Augustine of Hippo (5th Century): While not teaching OSAS in its modern sense, Augustine laid foundational groundwork for later Reformed theology. In his debates with the Pelagians, he emphasized God's sovereign grace and predestination. He developed the doctrine of the "gift of perseverance" (donum perseverantiae), arguing that those whom God has truly chosen will be given the grace to persevere in faith until the end. However, Augustine also believed that individuals could not know with infallible certitude in this life whether they had received this gift of final perseverance. This meant that a living believer could not be absolutely certain of their own final salvation. This nuance distinguishes his view from later OSAS interpretations.

• Early Church Fathers: Generally, the early Church Fathers (e.g., Justin Martyr, Irenaeus, Tertullian, Origen, Cyprian) did not teach "unconditional eternal security" as understood by modern OSAS. Many of their writings suggest that believers could, through grave sin or apostasy, forfeit their salvation, emphasizing the need for ongoing faith and obedience. Some scholars argue that early forms of "eternal security" were found in Gnostic heresies, which the Church Fathers actively refuted.

II. The Protestant Reformation (16th Century)

The Reformation brought significant shifts in understanding salvation, which directly impacted the development of OSAS.

• Martin Luther (early 16th Century): While Luther championed Sola Fide (justification by faith alone), he did not explicitly teach OSAS in the strong sense that some later proponents would. He believed in the possibility of apostasy (falling away from faith) for believers, though he also emphasized God's preserving power. His focus was on the assurance of salvation in Christ, not on an automatic, irreversible state regardless of continued faith.

• John Calvin (mid-16th Century): Calvin is widely considered the key figure in systematizing the doctrine that would become known as the "Perseverance of the Saints."

  • Perseverance of the Saints: Calvin, in his Institutes of the Christian Religion (first published 1536, with later editions expanding on these points), taught that those who are truly elected by God and genuinely regenerated by the Holy Spirit will persevere in faith until the end. Their perseverance is a result of God's unchangeable purpose and preserving power, not their own merit. For Calvin, true faith is always a persevering faith. If someone falls away, it demonstrates they were never truly regenerate to begin with.

  • Assurance: While Calvin affirmed the believer's assurance of salvation, it was an assurance rooted in God's faithfulness and the work of the Spirit, not an assurance that allowed for a lack of ongoing spiritual fruit or a casual approach to sin.

III. Post-Reformation Developments (17th Century Onwards)

• Synod of Dort (1618-1619): This synod was convened by the Dutch Reformed Church to address the Arminian controversy. The Canons of Dort formally codified the "Five Points of Calvinism," with the fifth point being the "Perseverance of the Saints." This established the Reformed position that those truly called by God will be preserved by His power and will persevere in faith to the end. This was a definitive theological statement on the security of the believer within Reformed circles.

• Emergence of "Eternal Security" and "Once Saved, Always Saved" Terminology (Late 19th - Early 20th Centuries):

  • The specific phrases "eternal security" and "once saved, always saved" became more common and popularized in certain Evangelical Protestant groups, particularly within Southern Baptist circles (e.g., "security of the believers" in 1873) and among the Plymouth Brethren (e.g., "eternal security" in 1913).

  • These terms often emphasize the absolute and unconditional nature of salvation once received, sometimes leading to interpretations that diverge from the nuanced "Perseverance of the Saints" by downplaying the necessity of ongoing perseverance or good works as evidence of true faith.

• Free Grace Theology (20th Century):

  • This movement, significantly influenced by figures like Lewis Sperry Chafer (early 20th century) and later Charles Ryrie and Zane Hodges, further refined and emphasized a strong form of "eternal security."

  • Free Grace theology often distinguishes sharply between salvation (received by faith alone) and discipleship/rewards (which are impacted by works). Some interpretations within this camp suggest that a person who has made a "decision" for Christ is eternally saved, even if they subsequently live a life devoid of spiritual fruit or appear to "abandon" their faith. This is a point of significant debate even within Protestantism, with many Reformed and other evangelical traditions maintaining that genuine saving faith will inevitably produce good works and perseverance.

  • Prominent modern proponents of OSAS/Free Grace theology include figures like Charles Stanley (d. 2023) and Tony Evans.

In summary, while the concept of God's preserving grace has ancient roots (Augustine), the doctrine of the "Perseverance of the Saints" was systematically developed and formalized by John Calvin in the 16th century and codified at the Synod of Dort in the early 17th century. The more popular and sometimes more absolute phrasing of "Once Saved, Always Saved" or "Eternal Security" emerged and gained widespread traction within Evangelical Protestantism in the late 19th and 20th centuries, particularly within dispensationalist and certain Baptist traditions

Addressing some of the main scripture often used to support OSAS:

When examined in their original Greek, most of the key "once saved, always saved" proof texts actually emphasize ongoing, continuous action rather than past completed events. Let me break down the major ones:

John 10:28-29 - "No one can snatch them"

• διδωμι (didōmi) - "I give" - present tense, indicating continuous giving

• απολλυμι (apollymi) - "perish" - aorist subjunctive with double negative, meaning "shall never perish"

• αρπαζω (harpazō) - "snatch" - The protection is from external forces, but doesn't address internal apostasy

Key issue: This speaks about external threats, not internal decisions to abandon faith.

Ephesians 1:13-14 - "Sealed with the Spirit"

• σφραγιζω (sphragizō) - "sealed" - aorist passive, but the context shows this applies to "those who believed"

• πιστευω (pisteuō) - "believed" - aorist participle, but refers to the point of initial faith

Key issue: The sealing follows belief, but doesn't address what happens if belief ceases.

Romans 8:38-39 - "Nothing can separate us"

• χωριζω (chōrizō) - "separate" - The list is of external forces

• αγαπη (agapē) - "love of God" - Nothing external can separate us from God's love

Key issue: Again, this addresses external threats, not internal apostasy or rejection of faith.

Philippians 1:6 - "He will complete the work"

• επιτελεω (epiteleō) - "will complete" - Future tense, but the verse assumes continued faith

• Context: Paul is writing to faithful believers who are persevering

Romans 8:29-30 - The "Golden Chain"

• All verbs are aorist tense, but this describes God's eternal perspective

• Key issue: This is about God's predetermined plan, not individual perseverance regardless of faith

The strong adherence to OSAS despite biblical and historical evidence against it stems from several interrelated factors:

Historical Development:

• OSAS became prominent during the Protestant Reformation, particularly through John Calvin and later Reformed theology

• It was a reaction against perceived Catholic "works righteousness" - Reformers wanted to emphasize salvation by grace alone

• Puritan influence in America made Calvinist theology foundational to much of American evangelicalism

Psychological Appeal:

• Comfort and assurance - People naturally want security about their eternal destiny

• Removes anxiety about spiritual performance or "losing salvation"

• Appeals to human desire for certainty in an uncertain world

• Once-and-done mentality fits modern consumer culture

Denominational Identity:

• Many Baptist, Presbyterian, and Reformed denominations make OSAS a core distinctive

• Questioning it can mean questioning denominational identity

• Institutional momentum - once established, doctrines become self-perpetuating

• Seminary training reinforces denominational positions

Interpretive Framework:

• Systematic theology approach - fitting verses into predetermined theological systems

• Selective emphasis - highlighting supporting verses while minimizing contradictory ones

• Harmonization attempts - explaining away contrary evidence rather than revising the doctrine

Cultural Factors:

• American individualism - "personal relationship with Jesus" emphasis

• Decisionism - focus on "the moment you got saved"

• Evangelistic tool - easier to get conversions with guaranteed security

• Anti-Catholic sentiment historically made Protestant distinctives more entrenched

Emotional Investment: People often structure their entire spiritual identity around OSAS, so abandoning it feels like losing everything rather than just correcting one doctrine.

It's a classic case of tradition and comfort overriding careful biblical exegesis.