Therefore I tell you, every sin and blasphemy will be forgiven people, but the blasphemy against the Spirit will not be forgiven. And whoever speaks a word against the Son of Man will be forgiven, but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come. (Matthew 12:31-32)
There is a sin which will not be forgiven. It is here named “the blasphemy against the Spirit”. This certainly sounds like a frightening thing; a sin which would prevent you from ever being saved, and seal your destiny to hell. It doesn't sound like it would be a difficult sin to commit, either; perhaps inadvertently, even? But in order to clearly understand a passage of Scripture standing isolated from its context like this, we need to go and look at it in its context. This passage appears midway through Matthew 12. In order to understand this passage, I think we need to start at the beginning of Chapter 11.
In order to keep this post from becoming several pages long, let me summarize the relevant points from Matthew 11-12, and you can read them for yourselves. In the beginning of Chapter 11, John the Baptist, who had told the people that Jesus was the Christ (or “Messiah”), now has his doubts. So he sends some men to Jesus to ask Him whether or not He is, in fact, the Christ. Jesus' response is this: “Go and tell John what you hear and see: the blind receive their sight and the lame walk, lepers are cleansed and the deaf hear, and the dead are raised up, and the poor have good news preached to them.” That is to say, Jesus' miracles are clear evidence that He is the Christ. Then Jesus makes this point... that people went out to see John the Baptist, believing that he was a prophet. And this prophet did indeed prophesy that Jesus was the Christ. But some said that John “has a demon” (Matthew 11:18). And then when John's words came to pass and Jesus did begin His ministry, they scoffed at the claim that He was the Christ because He ate with sinners. Jesus is saying that people will blind themselves to the clear evidence before them, rather than believe in Christ. Then Jesus applies this to the people of His time saying that the condemnation of hell will be more severe for those who now reject Christ than it was for Sodom and Gomorrah, or for Tyre and Sidon; because these Old Testament cities that were judged by God for their rejection of Him had far less evidence of the reality of God.
Woe to you, Chorazin! Woe to you, Bethsaida! For if the mighty works done in you had been done in Tyre and Sidon, they would have repented long ago in sackcloth and ashes. But I tell you, it will be more bearable on the day of judgment for Tyre and Sidon than for you. (Matthew 11:21-22)
So the essential point of Chapter 11 has been about the unbeliever’s denial of the plain evidence that Jesus is the Christ, namely Jesus' miracles. If we skip ahead a little into Chapter 12, after Jesus has shown us the way in which the Pharisees have misunderstood the Scriptures, and after Jesus has performed a miracle in which He demonstrates mercy, Jesus performs another miracle in which He casts out a demon. The people seeing this wondered “Could this be the son of David?” That is to say, having seen this miracle (this evidence) they're wondering whether Jesus is the Christ! At this, the Pharisees make the accusation that Jesus performed the miracle by the power of “Beelzebul”, (or Satan). And we can recall how this was said of John the Baptist in Chapter 11, (verse 18). This is another example of how the unbeliever denies the plain evidence before him. But Jesus shows them their folly – “Every kingdom divided against itself is laid waste, and no city or house divided against itself will stand. And if Satan casts out Satan, he is divided against himself. How then will his kingdom stand?” Jesus is saying that Satan wouldn't oppose his own demons. But more than that, Jesus is introducing this spiritual idea of “two kingdoms”. There's the kingdom of God, and all who follow God; and then there's the kingdom of Satan, and all who follow him. Jesus continues, “But if it is by the Spirit of God that I cast out demons, then the kingdom of God has come upon you.” That is to say, if there are only two kingdoms – the kingdom of God and the kingdom of Satan – and it doesn't make sense for Satan to cast out his own demon, then what they'd just seen must be evidence that Jesus is of God's kingdom. And more than that, Jesus has a position in that kingdom of power and authority over Satan. There are only two kingdoms, and you are on the side of one or the other. You cannot be on “both” or “neither”. Jesus continues...
Whoever is not with me is against me, and whoever does not gather with me scatters. Therefore I tell you, every sin and blasphemy will be forgiven people, but the blasphemy against the Spirit will not be forgiven. And whoever speaks a word against the Son of Man will be forgiven, but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come. (Matthew 12:30-32)
This “blasphemy of the Holy Spirit” is like the blasphemy one speaks against a king. When you see the undeniable evidence of the kingdom of God, and yet deny it by turning a blind eye to it, that's blasphemy of the Holy Spirit. And we do have an abundance of evidence all around us. We have the evidence of Creation itself to the existence of God, and we have the Bible which is the testimony of Christ, and we have the witness of the Church.
Now denying this evidence seems like something that every person is likely to have done at some point. Well, I think it probably is. Jesus now goes on to say “Either make the tree good and its fruit good, or make the tree bad and its fruit bad, for the tree is known by its fruit.” (Matthew 12:33) This metaphor of the tree is one that Jesus used in the Sermon on the Mount, and it speaks of regeneration. Unless a person is regenerated by God they are a “bad tree”, and a bad tree is going to speak blasphemies like this. But if we should turn to God with a hunger and a thirst for righteousness, then God gives us a new heart to honour and serve Him as our king – our Lord and Saviour. What the unforgivable sin is all about is rejecting the work of the Holy Spirit in your life as He reveals the truth about Jesus to you. If you fully and finally reject Him, there is no other Saviour and you cannot be forgiven. Rather, you will be given exactly what you have desired; to be under the dominion of Satan for the rest of eternity.
Cast away from you all the transgressions that you have committed, and make yourselves a new heart and a new spirit! Why will you die, O house of Israel? For I have no pleasure in the death of anyone, declares the Lord GOD; so turn, and live. (Ezekiel 18:31-32)