Impeccability is the doctrine that Jesus Christ, as the eternal Son of God incarnate, could not sin — not merely did not sin. This is the majority position of orthodox Christology. The argument runs: God cannot sin (James 1:13; Numbers 23:19). Jesus is God (John 1:1; Colossians 2:9). Therefore Jesus cannot sin. His human nature, though real and complete, was so perfectly united with his divine nature in the one Person of the Son that the divine nature governed the human. This does not make Christ's temptations unreal (Hebrews 4:15) — he was genuinely assaulted by temptation and genuinely felt its weight. A bar of iron thrust into fire does not burn — not because fire is cool, but because the iron's nature prevents it. So Christ felt the full force of temptation and resisted not by struggle but by nature. His holiness is the foundation of our redemption: only a perfectly holy sacrifice could atone.
Peccability: The possibility of sinning. Held by those who argue Christ could have sinned but didn't. Concern: makes Christ's temptation "real" in a way the impeccabilist denies.
Impeccability: The impossibility of sinning. Held by the orthodox majority. The temptations were real assaults; Christ's resistance was certain and guaranteed by his divine nature — not because the temptations were fake, but because his Person is incorruptible.
Sinlessness: The fact that Jesus committed no sin — a point on which all orthodox Christians agree, whatever their position on the deeper peccability question.
A Christ who could have sinned is a Christ whose obedience was contingent, whose atonement was uncertain until the last moment, and whose nature is more analogous to a very good human than to God in flesh. The impeccability of Christ is not theological hairsplitting — it is the bedrock of assurance. We do not hope in one who barely succeeded. We hope in one for whom holiness is not achievement but essence. A peccable savior offers us a peccable salvation. Only the impeccable Son can make imputed righteousness real.
Hebrews 4:15 — "For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin."
2 Corinthians 5:21 — "For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God."
1 Peter 2:22 — "He committed no sin, neither was deceit found in his mouth."
John 8:46 — "Which one of you convicts me of sin?"
Hebrews 7:26 — "For it was fitting that we should have such a high priest, holy, innocent, unstained, separated from sinners."
G264 — ἁμαρτάνω (hamartanō): "to sin, to miss the mark" — from which we derive hamartia; what Christ never did
G53 — ἁγνός (hagnos): "holy, pure, undefiled" — used of Christ's moral purity that qualifies him as sacrifice
G3741 — ὅσιος (hosios): "holy, devout, undefiled" — one of the Hebrews 7:26 descriptors of Christ as high priest
"The impeccability of Christ is not a cold philosophical abstraction — it is the warm ground beneath every believer's feet. He did not hold on by his fingernails. He cannot fail."
"Jesus was tempted in every way as we are — and felt that temptation fully — yet his impeccability means the outcome was never in doubt. Fire cannot burn the Son of God."
"A peccable Savior is not good news. Only the impeccability of the eternal Son makes the atonement certain, the righteousness real, and the hope unshakeable."