There is a particularly disgusting effort on the part of Matthew to slander the Pharisees with having committed the unpardonable sin. His libel deserves a thorough investigation.
The first instance is rather brief,
While they were going out, a man who was demon-possessed and could not talk was brought to Jesus. And when the demon was driven out, the man who had been mute spoke. The crowd was amazed and said, "Nothing like this has ever been seen in Israel." But the Pharisees said, "It is by the prince of demons that he drives out demons."(Matthew 9:32-34)
Matthew's gospel is obsessed with demons and demon-possession, but the Jewish world was not.
Flavius Josephus mentions demons three times only: (1) playing the harp exorcized the "evil spirit" that beset Saul, (2) the souls of those killed in battle become "good demons" and "propitious heroes" (The History of the Destruction of Jerusalem; Book VI, Chapter 1, par. 5) and (3) King Solomon had the ability to expel demons,
Solomon bequeathed exorcisms which retain a great authority unto this day and which guarantee that demons never return, for I have seen a Jew named Eleazar releasing demon-possessed people in the presence of Vespasian, his sons, captains and a multitude of soldiers. The manner of the exorcism was this: Eleazar took a ring with a Foot of the type described by Solomon, put it to the nostrils of a demon-possessed man and drew out the demon through the afflicted man's nose. The man fell down immediately and Eleazar abjured the demon in the name of Solomon, then recited the ancient incantations devised for the demon to never return. And Eleazar demonstrated his power by ordering the departing demon to overturn a receptacle full of water placed a short distance away. This he did, whereupon Solomon's skill and wisdom was displayed very manifestly.(Antiquities of the Jews. Book VIII, Chapter 2, par. 5. Edited)
Philo of Alexandria states that what Moses calls "angels" other philosophers term "demons" (On the Giants, II, 6) and that the "evil angels" of Psalm 77:49 ("destroying angels," some Bibles) really tab those wicked men who, unfamiliar with the sciences and with the virtues, pursue the pleasures available to the eye, ear, taste, belly or genitalia (Ibid., IV, 16-18).
In other words, the construction of an elaborate demonic realm was a "modern" creation.
The remainder of this chapter analyzes the second libel (Matthew 12:22-37).
Matthew 12:22 again links a man's physical disability (blind and mute) to the work of a demon. Generalizing his retrogressive premise implies that every illness or physical disability is the work of a demon, and consequently a near-sighted individual "should" see an exorcist instead of an optometrist.
Matthew 12:24 has the Pharisees (who adhered to "the conduct of reason") style Beelzebub the "prince of demons"; but Beelzebub was not a contemporary deity and he had been a town's god of an insignificant nation (Isaiah 14:28-32).
Jesus speaks about a kingdom of Satan on Matthew 12:25-26. In Christianity Satan is a king, but in Judaism he is God's curmudgeon and he is hardly ever mentioned.
Matthew 12:28 has Jesus say that his exorcisms connoted the arrival of the kingdom of God but, again, his statement is not Jewish because King David depicted the kingdom of God as the static greatness, power, glory, majesty and splendor of heaven and earth (1 Chronicles 29:11-12). In other words the kingdom of God is always present from everlasting to everlasting.
Finally the unpardonable sin is not a question of words spoken against a Holy Spirit (Matthew 12:31-32) but a question of how you define good and evil. The Old Testament puts it this way, "Woe to those who call evil good and good evil, who put darkness for light and light for darkness, who put bitter for sweet and sweet for bitter" (Isaiah 5:20).
Aside for the thoughtful reader
Matthew 12:29 betrays the existence of multiple authors because it garbles the logic of preceding verses. "Driving out demons" is not the same as "robbing a strong man's house" because a "demon-possessed" individual is equivalent to the house of a weak man which gets broken into by a strong burglar. Rather "driving out demons" is equivalent to "flushing out" a strong burglar from a weak man's house.
Conspicuously Matthew 12:32, "Anyone who speaks a word against the Son of Man will be forgiven, but anyone who speaks against the Holy Spirit will not be forgiven either in this age or in the age to come," refutes the Christian dogma of the Trinity, for how can God forgive and forget on the one hand and yet refrain from forgiving and forgetting on the other?
Matthew 12:30, "He who is not with me is against me, and he who does not gather with me scatters," is an orphaned verse; context missing, interpretation prone to error.
Matthew 12:33 is another orphaned verse; but this one fits well inside an unrelated passage dealing with false prophets,
Watch out for false prophets. They come to you in sheep's clothing, but they are ferocious wolves inwardly. You will recognize them by their fruit. Do people pick grapes from thornbushes, or figs from thistles? Likewise every good tree bears good fruit, but a bad tree bears bad fruit. Make a tree good and its fruit will be good, or make a tree bad and its fruit will be bad, for a tree is recognized by its fruit. A good tree cannot bear bad fruit, and a bad tree cannot bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus, by their fruit you will recognize them.(Matthew 7:15-17, 12:33, 7:18-20)
The wearisome dull repetition is evidence of impromptu contributors.
Finally Matthew 12:37, "For by your words you will be acquitted, and by your words you will be condemned," appears to contradict what Jesus says about false prophets. More importantly, it again exposes just how disheveled this gospel is!