It is one of the more intriguing but also difficult, and sometimes frightening passages in the New Testament. Jesus said, “Assuredly, I say to you, all sins will be forgiven the sons of men, and whatever blasphemies they may utter; but he who blasphemes against the Holy Spirit never has forgiveness, but is subject to eternal condemnation” (Mark 3:28-29; cf. Matt. 12:24-32). The idea of an “unpardonable sin” is unsettling. What is the blasphemy of the Holy Spirit? Can it be committed today?
As with any difficult text in Scripture, it is paramount to first understand it in its context. The context of Mark 3:20-35 is one of opposition and rejection. First, by Jesus’ own family (Mark 3:20-21, 31-35) and second, by a delegation of scribes (Mark 3:22-30) and Pharisees (Matt. 12:24). His family members accused Him of being crazy and the Jewish leaders accused Him of casting out demons by the power of Satan, thus being demon possessed, Himself.
Jesus answered the scribe’s accusation by issuing a refutation and conclusion followed by a warning. First, to suggest that Satan would cast out his own demons is absurd. It’s a self-defeating scenario which would result in Satan promulgating his own destruction (Mark 3:23-26). Second, the fact that Jesus was casting out demons by the power of God– not Satan–implies the reality of the Kingdom (Matt. 12:28) and the ultimate defeat of the Devil (Mark 3:27). Jesus had entered into the strong man’s (Satan) domain and was seizing his goods (the people being freed by exorcising demons). Finally, the warning. To attribute the work of God to Satan (note v. 30) is a sin which cannot be forgiven. Thus, in context, the blasphemy of the Holy Spirit is the attributing of Jesus’ miraculous power to the Devil.
It is impossible to blaspheme the Holy Spirit in the same way that the Scribes and Pharisees did because Jesus is no longer here performing miracles. In fact, there are no miracles being performed today (cf. 1 Cor. 13:10). But, like them, we can commit an “unpardonable sin” in the sense that we stand in willful and defiant rejection of God. We cannot be forgiven if we reject the Forgiver. A doctor may prescribe medication to resolve an illness but a person cannot be cured if they refuse the medication. But, if he repents and takes the medicine, he will be cured. So it is with one who repents of their rejection of Christ. There is no “unforgivable sin” unless one refuses to repent.