One of the striking features about the mass of biblical evidence about conversion is the huge diversity in the kinds of sinners that have been converted. Blasphemers, thieves, fornicators, murderers, the covetous, the foolish, the pharisaical. All sorts of sins, all sorts of sinners, have been and can be forgiven.
Which makes it difficult to know what to make of the unforgiveable sin. It is a fearfully troublesome thought, the consideration that the God of all grace, whose work is to save, deals with some sinners as having committed a sin which is ‘unto death’. But we know that not every blasphemous word spoken against the Holy Spirit is unforgiveable – not every rejection of Christ, not every turning your back on the means of grace – because sinners who were guilty of all these things have been saved. At one stage they had abandoned their praying and bible-reading and churchgoing, and were resisting salvation by Christ, and had dishonoured the Holy Spirit – but subsequently they were forgiven and converted.
If characteristics can be provided of someone who has committed the unforgiveable sin, they would seem to include a kind of hardness against anything related to God and the gospel, accompanied by a spirit of deliberate malice and hatred against the Saviour, in the context of having previously had such acquaintance with the gospel and the way of salvation that they know full well how spiteful and baseless their attitude now is. People who are afraid they may have committed the unpardonable sin, haven’t. Such a fear is incompatible with the shameless, flaunting, knowing derision which is directed against the gospel by those who have committed it.
Of course, when a person is confronted with the gospel – that a full and free salvation is provided by Christ and that whosoever believes in him shall be saved – there’s no excuse ever for rejecting it and treating it with disbelief or unbelief. But although this is the default sin of humankind, and it can’t be avoided that this sin itself “deserves God’s wrath and curse,” and should be repented of immediately, yet for as long as it is not accompanied by those extra characteristics, I don’t think it can be called the unforgiveable sin.
This is still true in cases where people used to attend church (and maybe made a profession of being converted) but have subsequently fallen away. There are many reasons why a person could end up where they no longer think they are a Christian, without having committed the unforgiveable sin. Perhaps they were converted but have slipped into a sluggish, worldly, backslidden condition where their prayer should be, “Draw me and I will run after thee; heal my backslidings and love me freely.”
Or perhaps they never were converted in the first place: lots of people don’t know very well what makes them claim to be a Christian, there are plenty ‘nominal’ Christians whose spiritual experience never went heart-deep, and many people rely too much on the opinion and encouragement of their churchgoing friends in deciding their spiritual status rather than giving scriptural diligence to make their calling and election sure. These people’s prayer should be, “Lord, show me myself, and show me thyself; God be merciful to me a sinner.”
In the end, the priority has to be to obtain mercy while mercy is available. The scriptures urge this on us: there is plenteous redemption to be found, but the opportunity to find it may not continue indefinitely. Seek ye the Lord while he may be found, call ye upon him while he is near. Let the wicked forsake his way, and the unrighteous man his thoughts, and let him return to the Lord, for he will have mercy on him, and to our God, for he will abundantly pardon.