There are two sins that claim a pre-eminence in hell—hypocrisy and unbelief; and therefore other sinners are threatened to ‘have their portion with the hypocrites,’ Matt. 24:51, and ‘with unbelievers,’ Luke 12:46; as if those infernal mansions were taken up principally for these, and all others were but inferior prisoners. But of the two unbelief is the greater, and that which may, with an emphasis, be called above this or any other, ‘the damning sin.’ ‘He that believeth not is condemned already,’ John 3:18. He hath his mittimus already to jail; yea, he is in it already in a sense—he hath the brand of a damned person on him. The Jews are said, Rom. 11.32, to be shut up ‘in unbelief.’ A surer prison the devil cannot keep a sinner in. Faith shuts the soul up in the promise of life and happiness, as God shut Noah into the ark. It is said, ‘the Lord shut him in,’ Gen. 7:16. Thus faith shuts the soul up in Christ, and the ark of his covenant, from all fear of danger from heaven or hell; and [thus too,] on the contrary, unbelief shuts a soul up in guilt and wrath, that there is no more possibility for an unbeliever of escaping damnation, than for one to escape burning that is shut up in a fiery oven. No help can come to the sinner so long as this bolt of unbelief is on the door of his heart. As our salvation is attributed to faith, rather than to other graces —though none [be] wanting in a saved person—so sinners’ damnation and ruin is attributed to their unbelief, though the other sins [are] found with it in the person damned. The Spirit of God passeth over the Jews’ hypocrisy, murmuring, rebellion, and lays their destruction at the door of this one sin of unbelief. ‘They could not enter in because of unbelief,’ Heb. 3:19.
O sinners!—you who live under the gospel I mean—if you perish, know beforehand what is your undoing—it is your unbelief that does it. If a malefactor that is condemned to die be offered his life by the judge upon reading a psalm of mercy, and he reads not, we may say his not reading hangs him. The promise of the gospel is this psalm of mercy, which God offers in his son to law‑condemned sinners. Believing is reading this psalm of mercy. If thou believest not and are damned, thou goest to hell rather for thy final unbelief than any of thy other sins, for which a discharge is offered thee upon thy receiving Christ and believing on him. Let this cause us all to rise up against this sin, as the Philistines did against Samson, whom they called the destroyer of their country,’ Judges 16:24. This is the destroyer of your souls, and that is worse; yea, it destroys them with a bloodier hand than other sins do that are not aggravated with this. We find two general heads of indictments upon which the whole world of sinners shall be condemned at the great day, II Thes. 1:8. There Christ’s coming to judgment is expressed; and those miserable undone creatures that shall fall under his condemning sentence, are comprised in these two [classes]—such as ‘know not God,’ and such as ‘obey not the gospel of Jesus Christ.’ The heathens' negative unbelief of the gospel shall not be charged upon them, because they never had it preached to them. No; they shall be sent to hell for ‘not knowing God,’ and so shall escape with a lighter damnation by far, than Jews or Christian Gentiles to whom the gospel hath been preached —though to some of these with a stronger and longer continued beam of light than [has been the lot of] others. The dismal charge which shall be brought against these will be, that they have not obeyed the gospel of our Lord Jesus; that is, not believed on Christ—called therefore the ‘obedience of faith,’ Rom. 16.26. And certainly, we cannot but think that there shall be a torment proper to these gospel refusers, which those that never had the offer of grace shall not feel, in hell. And among those that obey not the gospel the greatest vengeance waits for them that have had the longest and most passionate treaty of mercy allowed them. These are they that put God to the greatest expense of mercy, and therefore they must necessarily expect the greatest proportion of wrath and vengeance to be measured to them; yea, their unbelief puts Christ, and the grace of God in him, to the greatest shame and scorn that is possible for creatures to do; and it is but righteous that God should therefore put their unbelief and themselves with it to the greatest shame before men and angels, of any other sinners.