This transgression is commonly called “the unpardonable sin,” something so grave that it will not be forgiven, either in the present age or in the next one, even though God is normally eager to forgive.
Blasphemy is not talked about much these days, since our culture cares little about the things of God. The word “blasphemy” comes from two roots that together mean “injurious speaking.” Granted, speaking (or writing) that causes injury is quite common these days, but blasphemy belongs in a separate category because it has God or something sacred as its target. Thus, blasphemy is “a dishonoring of God or sacred things,” whether done deliberately or not.
Jesus' words in Matthew 12 are a strong enough warning by themselves, but the parallel account in Mark 3:29 makes the consequences of this even more plain: “He who blasphemes against the Holy Spirit never has forgiveness, but is subject to eternal condemnation” (emphasis added).
The wider context of these verses helps us to understand this stark warning, beginning in Matthew 12:22 with Christ healing a demon-possessed blind-mute. Because of the Pharisees' hard hearts, they would not accept that this had been done through the power of the Holy Spirit, so they tried to diminish this work of God by claiming it was performed by the power of Satan.
In verse 33, Jesus says to evaluate a matter based on the fruit that is produced. The Pharisees should have been able to see the supremely positive fruit that He was producing, and at the same time, He was pointing out that the fruit they were producing was rotten. In verses 34-35, their speaking evil against the power of God reflected the evil in their own hearts. While the Pharisees belittled the miracle that had just taken place, Jesus says in verse 36 that even idle or careless words must be accounted for in the Day of Judgment. Verse 37 warns that our words will either justify us or condemn us, putting the Pharisees on thin ice.
Notice, though, that He does not state directly that these Pharisees had committed the unpardonable sin. They did commit blasphemy serious enough to evoke a thunderous warning, but it appears that Jesus may have made some allowance for the Pharisees because, in His taking on the form of a bondservant (Philippians 2:7), they were confused about who He was. His true identity as the Son of God had not been revealed to them (as it had been to the disciples; Matthew 16:16-17), so He declared that they could be forgiven the blasphemous things they said about Him. He did not mean that blasphemy or other sins are no big deal, but rather that it is possible for those things to be forgiven upon repentance, in contrast to a transgression that cannot be forgiven at all.
Remember, the Pharisees triggered this warning by attributing the outworking of God to the Lord of Flies (Beelzebub). It included a rejection of God's nature, power, and activity. The conversation between Christ and Nicodemus shows that some of the Pharisees would acknowledge that Jesus was a Teacher sent by God (John 3:1-2). Yet, Matthew 12:14 states that these Pharisees were plotting against Him, so they had malicious intent.
Even so, a measure of ignorance remained. Paul says in I Corinthians 2:8 that if the rulers of the age—which would include the Pharisees—had full comprehension, they would not have crucified the Lord of Glory. Despite their attitudes approaching the point where they would be unable to repent, their lack of full comprehension of who they were opposing meant that repentance could still be possible once their eyes are opened. Due to their ignorance, they were not guilty of conscious rejection of the Spirit of the Most High God.
David C. Grabbe
What Is Blasphemy of the Holy Spirit?
This is the unpardonable sin. It says if a Christian commits blasphemy against the Holy Spirit, there is no forgiveness for it. What does He mean? He is pronouncing the terrible fate of those who choose the wrong side. If we blaspheme the Spirit of God, which is God's power and the agency by which He works, we have determined that God has no power. This is, of course, a lie, because, as He just explained in the Parable of the Strong Man (Matthew 12:29), God is the most powerful Being.
If we deny God's power, it is denying God Himself. He says a person can blaspheme the Son of God, but try blaspheming God's power! Doing so makes Him into something else—it changes His nature (Romans 1:22-23)—and that is unforgivable. So we must choose our side carefully, because if we blaspheme what God is able to do, guess where we end up? In the Lake of Fire.
There is more to the unpardonable sin, but this is part of it.
Richard T. Ritenbaugh
Parables of Matthew 13 (Part 2): Leaven
Christ's ominous warning was prompted by the Pharisees' attribution of God's work, by His Spirit, to an unclean (demonic) source. In principle, we may be guilty of something similar if we are so set in our opinions that we are unwilling to acknowledge the activity of God in His other children.
The scattering of the church seems to have encouraged a change in perception from the one extreme of believing that everyone associated with the church is converted to the other extreme of suspecting that everyone who is not just like us must be unconverted. Truly, there is a fine line here, since we are required to evaluate fruit and discern what is of God and what is not. With all of the scriptural warnings about false teaching, teachers, and even brethren, we understand the necessity to compare words and deeds with the Word of God and to reject what is not of Him. We dare not underestimate the risk of deception.
On the other hand, though, another grave danger lurks in concluding that someone is unconverted because of some failing we observe in him or her. It may be that we are correct in our judgment, and our words will justify rather than condemn us. Yet, consider for a moment what is at stake if we speak idle words and misjudge this matter: It means we are attributing the work of God in that person's life—the faith, the overcoming, any good fruit—to something other than God. We may not be able to see all that He has done, but we are deciding it is nothing!
Can we grasp what transpires when we do such a thing? We are casting aspersions on the priceless Sacrifice substituted for that person. We are declaring the holy covenant that God made with that person to be null and void. We are insulting the Spirit of grace in that person's life (see Hebrews 6:4-8). Is it really worth risking that sort of evil speaking against something that is sacred?—against a beloved child of the Most High God?
Consider Paul's early experience with the church (see Acts 9). He did horrible things to holy people, and he did it with a clear conscience because he was sure he was right. He thought he was serving God by opposing the heretics—until that same God knocked him flat and told him that he was persecuting his own Maker. Decades after the fact, he was still lamenting his violence and contrariness toward people in whom the Holy Spirit dwelled. So terrible were his actions in his own sight that he did not even consider himself worthy to be called an apostle (I Corinthians 15:9). What he did was similar to what the Pharisees did in Matthew 12—he misjudged the activity of the Holy Spirit. But he also acted in ignorance, so he repented when God allowed him to see.
As Isaiah 55:8-9 says, God's thoughts are so much higher than ours. It is when we start thinking too highly of our own thoughts that we begin grieving, resisting, or even quenching the Spirit of God. God gives us these strong warnings because it is possible for us to ascend above the heights of the clouds in our own thoughts, and to arrive at the point where the mind, power, and nature of God become unrecognizable and objects of scorn. Jesus' warning should prompt us to evaluate our actions and words to ensure that we are not in any way opposing the Spirit of God.
David C. Grabbe
What Is Blasphemy of the Holy Spirit?
Blasphemy against the Holy Spirit is the denial by the witness of his life that an individual was forgiven, received God's Holy Spirit, and then failed to live by faith, returning to a life of sin.
John W. Ritenbaugh
Living By Faith and God's Grace
Other Forerunner Commentary entries containing Matthew 12:31: