NOW READ THE REST OF VERSE MATTHEW 12:30-32:
(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."
What that verse means, is that if they claim themselves to be religious, and they end up speaking sacrilegiously about God by any means such as (profaning his name, insulting the Spirit of grace, or sinning deliberately), they will not be forgiven. They will lose their reward (which they never did possessed to begin with), and will not make it into the Kingdom of God. Also, if they end up turning away from the faith to follow other Gods (a.k.a. carved idols/sacred stones/graven images) that cannot hear, talk, nor walk as well as to follow other religions (i.e. of Satan), than that too will be considered blasphemy because that will be forsaking God by sinning against him as well as rejecting his Son Jesus Christ along with the word of God which is the bible. There is no forgiveness for those who did not stand firm in the faith, they will lose their reward, and will not make it into the Kingdom of God.
If you seek him, he will be found by you; but if you forsake him, he will reject you forever (1 Chronicles 28:9).
Those who gone astray do not count as those who blasphemed against the Holy Spirit. They only blaspheme against Jesus Christ (a.k.a. the Son of Man) due to (preaching) false teachings about him or due to slandering his name. Let's say if one day a person decide to neglect false teachers to follow God's one and only son Jesus Christ as well as the entire bible, they will be forgiven. If they get baptized for the remission of sins, and receive the gift of the Holy Spirit, they will also be forgiven.
Like with Paul for example, Paul was exactly like the Pagans who use to misuse God's name, but wound up turning away from Satan to follow Jesus and God in the end, as a result, he was forgiven. Why was he forgiven? Because he believed and repented.
However, the Pharisees, the Sadduccees, and the Teachers of the Law blasphemed against God and against the Holy Spirit because they were against Christ/the teachings of Christ and the idea of the Holy Spirit to begin with even though they claim to be servants of God. Judas blaspheme against God and the Holy Spirit as well because he was of God in the beginning (meaning that he belong to God), but he end up doing a blasphemous thing by having Jesus killed on the cross, so he will not be forgiven. He had forsaking God and had portrayed Jesus which he will end up having to face God's judgment on the day of the Lord (a.k.a. The Second Coming of Jesus Christ); read (Matthew 26:14-25). Peter also portrayed Jesus due to the fact that he denied Christ, but eventually he was forgiven; read Matthew 26:31-35, Luke 22:54-62, and Acts 26:1-19. You might ask yourself, why was Peter forgiven and not Judas? It's because Judas committed suicide after the fact that he quenched the Holy Spirit. Read Acts 1:12-26. Judas didn't repent for the malicious act that he committed against God's Son, he just committed suicide which showed that his cowardliness will not lead him to repentance, but a curse. On the other hand, the Lord Jesus Christ show compassion over Peter's remorse, and so he saved Peter from getting killed by Herod the Pilate by letting him out/go freely. Peter demonstrated his character by instant repentance, that was why in the beginning, Jesus asked Him three times, "Peter will you feed my sheep (John 21:15-17)." He asked him this three times about feeding his sheep because he knew that Peter will not fall away completely, but will receive forgiveness, and will lead his sheep for him after his death.
In the book of 1 Samuel 2, it mentions about Eli's sons who had no regard for the Lord or the practices that comes with. They were wicked, immoral, and didn't like being rebuked by their own father for their sins.
According to verse (1 Samuel 2:25), it stays, "If a man sins against another man, God may mediate for him; but if a man sins against the Lord, who will intercede for him? His sons, however, did not listen to their fathers rebuke, for it was the Lords will to put them to death."
(Proverbs 29:1) A man who remains stiff-necked after many rebukes will suddenly be destroyed--without remedy.
I will back up my statements with these verses so that you will have a better understanding of what I am saying.
HERE ARE THE WARNING VERSES THAT ARE ABOUT BLASPHEMING AGAINST GOD AND THE HOLY SPIRIT:
(Deuteronomy 29:19-21) When such a person hears the words of this oath, he invokes a blessing on himself and therefore thinks, I will be safe, even though I persist in going my own way. This will bring disaster on the watered land as well as the dry. The Lord will never be willing to forgive him; his wrath and zeal will burn against that man. All the curses written in this book will fall upon him, and the Lord will blot out his name from under heaven. The Lord will single him out from all the tribes of Israel for disaster, according to all the curses of the covenant written in this Book of the Law.
(Hebrew 10:26-31) If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, but only a fearful expectation of judgment and of raging fire that will consume the enemies of God. Anyone who rejected the law of Moses died without mercy on the testimony of two or three witnesses. How much more severely do you think a man deserves to be punished who has trampled the Son of God under foot, who has treated as an unholy thing the blood of the covenant that sanctified him, and who has insulted the Spirit of grace? For we know him who said, It is mine to avenge; I will repay, and again, The Lord will judge his people. It is a dreadful thing to fall into the hands of the living God.
(2 Peter 2:20-22) If they have escaped the corruption of the world by knowing our Lord and Savior Jesus Christ and are again entangled in it and overcome, they are worse off at the end than they were at the beginning. It would have been better for them not to have known the way of righteousness, than to have known it and then to turn their backs on the sacred command that was passed on to them. Of them the proverbs are true: A dog returns to its vomit, and, A sow that is washed goes back to her wallowing in the mud.
(Hebrews 6:4-8) It is impossible for those who have once been enlightened, who have tasted the heavenly gift, who have shared in the Holy Spirit, who have tasted the goodness of the word of God and the powers of the coming age, if they fall away, to be brought back to repentance, because to their loss they are crucifying the Son of God all over again and subjecting him to public disgrace.
Land that drinks in the rain often falling on it and that produces a crop useful to those for whom it is farmed receives the blessing of God. But land that produces thorns and thistles is worthless and is in danger of being cursed. In the end it will be burned.
FROM THE COMMANDMENTS:
(Numbers 15:30) "Anyone who sins defiantly, whether native-born or alien, blasphemes the LORD, and that person must be cut off from his people."
(Exodus 20:7) "You shall not misuse the name of the LORD your God, for the LORD will not hold anyone guiltless who misuses his name."
(Exodus 22:28) "Do not blaspheme God or curse the ruler of your people."
CONCLUSION:
So the saying is, is if we misuse God's name, that will be considered blasphemy, and if we forsake or insult the spirit of Grace, that will be considered blasphemy. And If we rebel against God, that also will be considered blasphemy.