What does it mean that God is a consuming fire?
The phrase "our God is a consuming fire" (Hebrews 12:29, quoting Deuteronomy 4:24) is one of the most searching statements in Scripture. Several things stand out in how the writers treat it.
It Is "Our" God — Not God Out of Christ
The first thing nearly every writer flags is the word "our." This is not a statement about God as distant Judge — it is a statement about the God believers know in grace.
J.N. Darby is characteristically direct:
J.N. Darby"We receive a kingdom that cannot be moved"; and calls us to serve God with true piety, because our God is a consuming fire; not — as people say — God out of Christ, but our God. This is His character in holy majesty and in righteous judgment of evil.
William Kelly presses the same point, showing that love and holiness are not in tension:
William KellyUndoubtedly "our" God is a consuming fire; notwithstanding is He our Father who loves us perfectly. And He loves us equally as "God." None the less does He hate sin, as He has proved in the cross of Christ; and He has given us a nature that hates sin, even Christ who lives in us as He died for us. Nothing more opposed to truth than making grace a veil or excuse for sin, as every believer confesses.
What the Fire Consumes
The fire is directed at everything inconsistent with God's nature — whether in the believer or in the creation at large.
Hamilton Smith puts it concisely:
Hamilton SmithLet us not forget that, though we know God in grace, nonetheless, "our God is a consuming fire." He will burn everything that is not of Himself, whether it be flesh in His people or a creation defiled by sin.
F.W. Grant writes similarly:
F.W. GrantLet us have grace therefore to serve God acceptably, with reverence and godly fear, for our God is a consuming fire. All that is not according to His mind is destined to that fire.
Morrish's Bible Dictionary captures both the purifying and judicial aspects:
Morrish's Bible DictionaryIn the N.T. it is repeated, "Our God is a consuming fire" (Heb. 12:29), to consume the dross in the Christian, as gold is tried and purified in the fire; and to judge and punish the wicked with unquenchable fire.
Godly Fear — Not the Terror of Sinai
The statement calls for reverence, not slavish dread. The context of Hebrews 12 is that believers have received an unshakeable kingdom — and it is precisely because the kingdom is secure that they are to serve with godly fear.
F.B. Hole draws this out beautifully:
F.B. HoleOur God — the Christian's God — is a consuming fire, and everything that is unsuited to Him will be devoured in His judgment... The feeblest believer is entitled to [contemplate that day] with calmness of spirit, for we receive, one and all, a kingdom which cannot be shaken.
Also let us take note that we are exhorted to serve God acceptably, not in order to have the kingdom made sure to us, but because we have received it, and it never can be moved. The very certainty of it, far from making us careless, only incites us to serve.
J. Wilson Smith holds the two truths together:
J. Wilson SmithGodly fear becomes the servants and worshippers of such a God as ours. He is spoken of in the succeeding chapter of our epistle as "the God of peace, who brought again from the dead our Lord Jesus Christ"; but though the God of peace He is, none the less, "a consuming fire." "God is love," but "God is light" as well. What reverence, what awe, should mark those who serve Him! What essential holiness must characterize His kingdom! Hence its stability.
No Refuge Beyond the Gospel
J.G. Bellett makes perhaps the most striking point — the fire of Sinai could be escaped by turning to Christ; but now that Christ has spoken from heaven, there is no further place of retreat:
J.G. BellettThen it very solemnly closes: "Our God is a consuming fire," that is, the God of this dispensation. From the fires of Sinai there was a relief by turning and taking refuge in Christ; but there is no relief if God's relief is despised. If you turn away from the relief this dispensation brings in, there is no more relief. "Our God is a consuming fire."
The Consuming Fire and God's Government
Samuel Ridout gives the fullest treatment, tying together the unshakeable kingdom and the fire:
Samuel RidoutThe time is coming when God will shake heaven and earth, the sea and the dry land; everything will be shaken but the Kingdom which cannot be moved, the Kingdom of divine grace, the Kingdom of Christ into which we have been brought... Let us have grace, then, whereby we may serve our God acceptably, with reverence and godly fear; for our God is a consuming fire (not merely as is sometimes said, that "God out of Christ is a consuming fire;") He will indeed not spare the adversaries, and will also judge His people's ways, both here and at the judgment-seat of Christ.
C.H. Mackintosh traces the proof of this in Israel's history:
C.H. MackintoshAll the nations of the earth may learn from Israel's marvellous history, that God must punish disobedience, and that, too, first of all, in His own. And if He has not spared His own people, what shall be the end of those who know Him not?... The government that could or would allow evil to go unjudged, uncondemned, unpunished, would not be a perfect government, would not be the government of God.
To draw the threads together: "Our God is a consuming fire" means that the God who has brought us near to Himself in grace is of such absolute holiness that everything inconsistent with His nature must be consumed — whether that is the "dross" of the flesh in the believer, or an entire creation defiled by sin. The word "our" is the key: this is not a threat flung at the unsaved from a distance, but an intimate reality for those who know God as Father. Grace does not weaken His holiness — the cross proved that. And it is precisely because the believer stands in an unshakeable kingdom, secured by the blood of Christ, that he can hear this word without terror and yet with the deepest reverence. As Bellett so searchingly puts it: from Sinai there was relief in turning to Christ; but if Christ Himself is refused, there is no more relief.