What is the Unforgivable Sin?
Here are a few things that the unforgivable is not.
1. It is not cursing the Holy Spirit or using God’s name in vain. Some people have been terribly troubled that they have committed this sin, because of blasphemous thoughts they have had, or even blasphemous words they have said. These are terrible sins, but Paul tells us that he himself was a blasphemer in 1 Tim 1:13. Perhaps some have feared that because their cursing was particularly connected to the Holy Spirit, that they had committed this sin. But I seriously doubt that Jesus was saying that a specific using the name of the third person of the Trinity (the Holy Spirit) in vain was in a different category than doing the same with one of the first two persons (Father or Son).
2. Neither is the unforgivable sin any form of sexual sin, whether fornication, adultery, or homosexuality. Again, we have examples in Scripture of people who committed terrible sexual sins, even incest and adultery, yet were forgiven and restored (for example, David and Lot)
3. The unforgivable sin is not abortion, murder, multiple murders, or even suicide. David and the Apostle Paul both stand as examples of men who were guilty of murder, yet found mercy and forgiveness. Again, all of these things are sins. And all of them deserve and receive God’s just wrath and judgment. But through faith in the ransom paying death of Jesus (Mark 10:45) all of these sins can be forgiven. That is why Jesus can say in verse 28: “all sins will be forgiven the children of man, and whatever blasphemies they utter.”
4. In light of a question I received yesterday, perhaps I should add one more thing that the unforgivable sin is not. It is not simply unbelief. Evidently, people have often thought that the one sin that could not be forgiven is the sin of unbelief. I think it has even been said that God forgives all sins and sends no one to hell for any of their sins except for the sin of unbelief. But there are numerous problems with that view. The most obvious problem is that in Rev. 21:8 and many other texts, the Scriptures teach that God does in fact judge men for their sinful deeds - and not just the sin of unbelief. Another problem is that prior to our coming to faith in Christ, all of us are guilty of the sin of unbelief (again, Paul is a case in point in 1 Timothy 1). Clearly, there is provision in Christ for the forgiveness of our unbelief.
So, what is the unforgivable sin? In light of the context of Mark 3, there is warrant to say that it is a particular kind of unbelief. The unforgivable sin is the settled refusal of Jesus’ claims in the face of indisputable evidence along with the insidious choice to instead attribute his miracles to the power of evil.
This is clear from the context. Verse 30 tells us why Jesus made this statement: “for they had said, ‘He has an unclean spirit.’" As William Barclay puts it: “these men had been able to look at the incarnate love of God and to think it the incarnate power of Satan.” The scribes believed that Jesus was “a sorcerer, invoking occult power,” says R. T. France. They were confronted with the undeniable power of the purest and most holy man to every walk the face of the earth, and such was their obstinate unbelief that rather than acknowledging the obvious, they concocted the most unbelievable and vilifying lie possible. They accused Jesus of being demon-possessed! So the unforgivable sin is this obstinate and willful rejection of truth with the choice to call Jesus demon possessed and evil rather than bow to his claims.
Most evangelical commentaries affirm this interpretation. R. T. France says, “The blasphemia referred to is the scribes’ accusation of demonic collusion and possession.” D. A. Carson defines the unforgivable sin as “thoughtfully, willfully, and self-consciously rejecting the work of the Spirit even though there can be no other explanation of Jesus’ exorcisms than that.” James Edwards calls it “a specific misjudgment that Jesus is motivated by evil rather than by good, that he is empowered by the devil rather than by God." This fits the context of the passage and makes the best sense of Jesus' words.
One of the insights we can gain from thinking through the meaning of this passage is the importance of interpreting a passage within its context. The real clues as to the meaning of Jesus' severe warning are embedded within the narrative in which his warning appears. Sticking to the context helps us avoid wrong-headed interpretations that could needlessly torture the consciences of genuine believers who have received forgiveness through the death of Christ.