Imagine a world where we’re born neutral—free to choose good, and without a bias toward evil. Sounds appealing… until we turn on the news. Or look in the mirror. The universal presence of evil, from playground bullying to genocide, from white lies to war crimes, demands an explanation. Alibis such as “bad choices” or “poor environment” just don’t cut it.

The Reformed doctrine of original sin isn’t a medieval relic designed to make us feel bad about ourselves. It’s the only coherent explanation for human brokenness, the necessity of grace, and the glory of the gospel. Original sin teaches that through Adam’s first transgression, all humanity inherited both guilt and a corrupted nature—we’re sinners by birth, even before we’re sinners by choice.

 

THE BIBLICAL FOUNDATION: ADAM’S SIN, OUR CONDEMNATION

The apostle Paul doesn’t mince words in Romans 5:12: Notice the past tense—all sinned in Adam. This isn’t about personal sins we commit as adults; it’s about a cosmic transaction that happened in the garden before any of us drew breath.

Paul drives the point home in Romans 5:18-19 with a parallel structure that’s impossible to miss: The logic is ironclad. One trespass brings condemnation to all. One act of righteousness brings justification to all. Adam’s disobedience made many sinners. Christ’s obedience makes many righteous. If we’re not condemned in Adam, we cannot be justified in Christ. The two federal headships stand or fall together.

Paul returns to this theme in 1 Corinthians 15:45-49, contrasting the first Adam with the second. We bear Adam’s image—corruption, mortality, spiritual death—before we bear Christ’s image through regeneration. Verse 22 states it plainly: “For as in Adam all die, so in Christ all will be made alive.”

 

ORIGINAL SIN DEFINED: MORE THAN BAD INFLUENCES

The Reformed position affirms two inseparable realities that together constitute original sin.

First, imputed guilt. Adam acted as our federal head, our legal representative. His sin is credited to our account just as Christ’s righteousness is credited to believers. Romans 5:18 leaves no room for ambiguity: one trespass brought “condemnation for all people.” Not potential condemnation. Not condemnation if they later sin. Actual, present, legal guilt.

Second, inherited corruption. We’re born with a nature inclined toward evil, “dead in trespasses and sins” (Ephesians 2:1), unable to please God or seek Him (Romans 8:7-8). This isn’t about learned behaviour or environmental influence. David’s confession in Psalm 51:5 captures it perfectly: “Surely I was sinful at birth, sinful from the time my mother conceived me.”

Here’s the key distinction: We’re not sinners because we sin; we sin because we’re sinners. The corruption precedes the action. This isn’t about individual sins we commit—it’s about a condition we inherit, a spiritual DNA corrupted at the source.

 

WHY THE VIRGIN BIRTH WASN’T OPTIONAL

If sin passes through the human bloodline like a genetic inheritance, how does God get a sinless Saviour into the world? The virgin birth wasn’t just a fulfilment of Isaiah’s prophecy—it was the only way to solve an impossible problem. Jesus needed to be fully human to represent us. Yet, He couldn’t enter humanity through the normal route without inheriting Adam’s guilt and corruption.

So God did something unprecedented. Absence of a human father ensured there was no connection to Adam’s condemned line. A human mother meant genuine humanity—flesh, blood, temptation, suffering. Conception by the Holy Spirit meant absolute sinlessness and divine nature united in one person.

This is why Paul calls Christ “the last Adam” (1 Corinthians 15:45)—He starts a brand new humanity precisely because He didn’t enter through the corrupted old one. Without original sin, the virgin birth is just a miracle story. With it, the virgin birth becomes the hinge of history: God’s surgical solution to rescue a condemned race without compromising either justice or mercy.

 

WHAT’S LOST WHEN WE REJECT ORIGINAL SIN

Denying or softening original sin creates a catastrophic domino effect that topples everything essential to Christianity.

The gospel becomes advice, not rescue. If we’re born neutral, we need moral guidance and better examples, not regeneration. Jesus becomes an inspiring teacher rather than the necessary Saviour. Grace becomes helpful rather than essential. The cross shifts from cosmic necessity to preferred option.

Human depravity becomes inexplicable. Why does evil persist across every culture and century? Why do toddlers lie without instruction? Why does every utopian project collapse into tyranny? Blaming circumstances for human wickedness fails spectacularly to explain the universal bent toward sin that transcends geography, education, and opportunity.

God’s justice gets questioned. If we’re born innocent, why does Scripture insist we must be born again? Why does God need to regenerate us? The entire biblical narrative of fall and redemption collapses into incoherence.

Christ’s work loses its glory. The cross becomes merely God’s reaction to bad human choices rather than the predetermined solution to constitutional human guilt. The beautiful imputation framework—our sin to Christ, His righteousness to us—becomes unnecessary and arbitrary. Salvation becomes synergistic rather than monergistic, and assurance evaporates.

 

THE ARMINIAN ALTERNATIVE: WHY IT FALLS SHORT

To be fair, Arminians don’t deny human sinfulness. Their view suggests Adam’s sin resulted in spiritual death and corruption for all humanity, but not imputed guilt. We’re born with a sin nature but become guilty only when we personally sin (though enabled by prevenient grace to respond to God).

But this position, while well-intentioned, creates more problems than it solves.

1. Romans 5:18 is explicit: “One trespass brought condemnation to all people.” Not potential condemnation contingent on future choices. Present, actual condemnation. The parallel requires that condemnation come through Adam the same way justification comes through Christ—by imputation, not imitation.
2. Consider the death of infants. Romans 5:14 notes that “death reigned from the time of Adam to the time of Moses, even over those who did not sin by breaking a command, as did Adam.” If death is the penalty for sin, and infants die, they must bear sin’s guilt—not just corruption, but actual legal culpability in Adam.
3. The parallel breaks down. The Arminian position says we’re condemned for our personal sin but saved by Christ’s imputed work. But Paul insists on symmetry: condemned in Adam, justified in Christ. Both are federal, both are representative, both involve imputation.
4. It undermines assurance. If guilt requires personal sin, then doesn’t justification require personal righteousness? The entire logic of imputation—the genius of the gospel—crumbles.

 

THE DOCTRINE THAT MAGNIFIES GRACE

Original sin is devastating news. And that’s precisely why it’s necessary. Only when we grasp the depth of our ruin can we marvel at the height of God’s rescue.

Here’s the glory of the gospel: We were condemned in Adam through no choice of our own; we’re justified in Christ through no merit of our own. Grace from start to finish. Sovereignty in salvation becomes not a threat to human dignity but the only hope for human redemption.

The beauty of this doctrine is profound. Original sin doesn’t excuse sin—it explains it. It doesn’t minimise personal responsibility—it reveals why we need supernatural transformation, and not just mere moral reformation. It shows us humanity’s problem isn’t fundamentally educational or environmental—it’s ontological. And only the virgin-born second Adam can undo what the first Adam did.

 

 

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RELATED FAQs

Did Augustine invent the doctrine of original sin, or is it biblical? Critics often claim Augustine imported this “pessimistic” doctrine into Christianity in the 4th century, but he was actually systematising what Scripture already taught. Early church fathers like Irenaeus (2nd century) explicitly taught Adam’s sin affected all his descendants. Cyprian (3rd century) defended infant baptism precisely because babies inherit Adam’s guilt. Augustine didn’t invent original sin—he defended it against Pelagius, who taught we’re born morally neutral. As RC Sproul noted, “The Reformation was a return to Augustine, and Augustine was a return to Paul.”

• How can God justly condemn us for Adam’s sin when we didn’t choose it? This objection assumes individualistic categories foreign to Scripture, which thinks covenantally and representatively. John Murray explained it this way: Adam wasn’t acting as a private individual but as humanity’s federal head, just as a president represents a nation. We don’t complain that we inherit our citizenship, physical traits, or family wealth without choosing them—representation is how human societies actually work. More importantly, as Jonathan Edwards argued, if we object to being condemned in Adam, we must also object to being saved in Christ, since both work by the same principle of imputation. We can’t cherry-pick which representative we want.
• What about Romans 5:12’s phrase “because all sinned”—doesn’t that mean personal sin? The Greek phrase eph’ hō has sparked debate, but Reformed scholars consistently argue it refers to Adam’s sin being imputed to all. Charles Hodge pointed out that verses 13-14 explicitly say people died even though they “did not sin by breaking a command, as did Adam”. If personal sin caused their death, Paul’s argument collapses. The phrase makes most sense as “in whom all sinned,” referring to our solidarity with Adam. John Piper summarises it well: “Adam sinned, and the rest of us got caught up in the consequences because we were ‘in him’—our representative head.”

• If we inherit guilt, why doesn’t the Bible explicitly say babies go to hell? Scripture actually leaves room for God’s mercy toward those who die in infancy while upholding original sin. Theologians like BB Warfield and Charles Spurgeon believed elect infants who die are saved through Christ’s atonement applied apart from conscious faith. David’s confidence about his deceased infant—”I will go to him, but he will not return to me” (2 Samuel 12:23)—suggests hope. The key is that even infants need redemption (they’re not innocent), but God can save them through Christ without them exercising adult faith. As Sproul put it, “All who are saved are saved by grace, including infants.”

How should original sin shape the way we evangelise and disciple? Understanding original sin transforms ministry from motivational speaking to urgent rescue. Tim Keller emphasised we must help people see they’re not fundamentally “good people who sometimes make mistakes” but rebels in need of a new heart. This means evangelism focuses on regeneration, not mere decision-making, and discipleship emphasises God’s transforming grace, not just behaviour modification. It also cultivates humility—pastors recognise that apart from grace, they’re no different from those they serve. As Martyn Lloyd-Jones put it, “The gospel is not good advice to be followed, but good news to be believed”—and original sin explains why we need news, not advice.

 

 

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