Many Christians have at one time or another wondered about the ‘unforgivable sin’—and whether they have committed it. This idea is usually synonymous with Jesus’ warning against ‘blaspheming the Holy Spirit’ (see Matthew 12; Mark 3; Luke 12). The nature of the so-called unforgivable sin, or blasphemy against the Spirit, is debated. The interpretation that I believe best fits the context of Jesus’ warning is to understand it as rejecting God’s Messiah, his Spirit-empowered Saviour. This may come as a relief to some readers. For, according to this view, everyone who confesses Christ as Lord and continues in faith cannot be guilty of the unforgivable sin. To put it another way, Christians cannot blaspheme the Spirit. This brings us to the focus of this doodle: apostasy and assurance.

As you may know, I am currently reading for my Masters degree. My dissertation is a consideration of rest, in Hebrews 3-4. But I won’t bore you with that (previously I published a post on the oft-quoted exhortation in Hebrews 10:24-25). Studying Hebrews has introduced me to the many issues and debates surrounding this rather mysterious epistle. One church father, Origen, famously quipped, ‘Concerning the authorship of Hebrews, only God knows.’ Elusive details aside, one of the most contested aspects within the book are the warning passages (2:1-4; 3:7-4:11; 5:11-6:12; 10:26-31;12:25-29). Though their language varies, there is a fairly evident thread: those who neglect God’s salvation will not be saved (2:3); an evil, unbelieving heart can cause you to fall away from the living God (3:12); those who fall away hold the Son in contempt (6:6); those who spurn the Son’s blood will be judged (10:29); and those who reject God speaking from heaven will not escape (12:25). In a word, these passages warn believers against apostasy.

We must bear in mind that these warnings were addressed to a Christian church. What is more, and you can test this for yourself by reading the epistle, most commentators agree that the readers had not yet embarked on this devastating course away from the God who speaks and saves through his Son. Many attempts have been made to alter the sense or intended audience of these warnings. So it is claimed that Hebrews was written to a mixed congregation containing everything from Christians of a ‘martyr standard’ to regular believers, some nominal attendees and even vocal unbelievers or apostates. Looking at modern churches, such a range is not unthinkable. But even if the epistle was written to a diverse group, there is absolutely no evidence within the text that these distinct groups are ever exclusively addressed. Hebrews exhorts the church corporately, as a group of believers in danger of walking away from their faith. Hebrews warns Christians against apostasy.

If the sea were filled with ink, writers would have nearly drained it with their equivocations about the (im)possibility of apostasy in Hebrews. At the bottom of this voluminous torrent of attempts to make Hebrews say something other than what it straightforwardly states is the claim that true believers cannot lose their salvation. So the warnings against apostasy become warnings directed at non-believers. Alternatively, the warnings are viewed as empty threats—all bark and not bite. How strange that God would warn those who haven’t professed faith against apostasy. In his excellent essay on the warning passages in Hebrews, Scot McKnight writes, “the book of Hebrews does teach conditional salvation.” In other words, apostasy is the very real rejection of Christ by those who previously professed faith in him. Apostasy is a fearful possibility for those who believe.

This brings us back to my first paragraph and the suggestion that the possibility of apostasy is actually assuring. Just as Jesus taught in the Gospels that only one sin is truly unforgivable - that is, rejecting him - so too Hebrews warns Christians against the only course of action that will expose them to God’s judgment: apostasy. As McKnight writes, “the only sin the author sees as capable of destroying a genuine believer’s faith is the sin of apostasy.” But how is this assuring? Well, I can know that no sin will separate me from the love of God in Christ Jesus. For there is no condemnation for those who are in Christ. Hebrews repeatedly and emphatically teaches that Christ’s effective death and eternal priesthood means we can boldly approach God with confidence and without fear. Hebrews assures us in light of Christ’s sacrifice. If apostasy is the only sin capable of destroying Christian faith then Hebrews offers believers great assurance. An assurance which is not grounded in a previous profession of faith but persevering faith in the God who saves.