Why Blasphemy against the Holy Spirit is the only Unforgivable Sin?
Which sin is unforgiveable?
God forgive everything except He will not forgive the blasphemy against His Holy Spirit.
Matt 12:31-32 - 31 "Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men. 32 Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come.
 Why? and How?
It is easy to interpret this as one more unforgiveable sin that not allow one to enter into the Kingdom of God or Heaven. But this will cause one theological conflict. Let us see this in detail.
Is there any other unforgiveable sin referred by God in the Bible?
Unbelief in Jesus is "the unforgiveable sin" that never allow any unbeliever of Jesus Christ to enter into Heaven.
Acts 4:12 - 10 let it be known to you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom you crucified, whom God raised from the dead, by Him this man stands here before you whole. 11 This is the 'stone which was rejected by you builders, which has become the chief cornerstone.' 12 Nor is there salvation in any other, for there is no other name under heaven given among men by which we must be saved."
John 3:16,18 - 16 For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life. 17 For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.18 He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God.
John 8:24 - 21 Then Jesus said to them again, "I am going away, and you will seek Me, and will die in your sin. Where I go you cannot come." 22 So the Jews said, "Will He kill Himself, because He says, 'Where I go you cannot come'?" 23 And He said to them, "You are from beneath; I am from above. You are of this world; I am not of this world. 24 Therefore I said to you that you will die in your sins; for if you do not believe that I am He, you will die in your sins."
Throughout the Bible it teaches that unbelief in Jesus/God never anyone to enter into heaven. So, unbelief in Jesus is "the unforgiveable sin"
If we say that blasphemy against His Holy Spirit is one more unforgiveable sin then we are adding one more condition to Good News or Gospel (Believe in Jesus - John 3:16,...., Just shall live by Faith - Rom 1:17, Obtain God's Righteousness apart from keeping the law - Rom 3:20).
 In other words it leads to say that we need to believe in Jesus and not blasphemy against His Holy Spirit.
If anyone teaches that you need to believe in Jesus + do, do, anything to enter into heaven then they are cult they are not true Christians. So, be careful in interpreting the passage like these.
The reference in Matt 12:31 and Mark 3:28 easily lead us to interpret this as an one more unforgiveable sin. The real in-depth context to interpret "the blasphemy against the Holy Spirit" is in Luke 12:8-10.
Luke 12:10 - 8 "Also I say to you, whoever confesses Me before men, him the Son of Man also will confess before the angels of God. 9 But he who denies Me before men will be denied before the angels of God. 10 And anyone who speaks a word against the Son of Man, it will be forgiven him; but to him who blasphemes against the Holy Spirit, it will not be forgiven.
God keeps on providing opportunity to everyone to give up their unbelief in God and Jesus Christ and believe in Him.
Acts 17:24-27 - 24 God, who made the world and everything in it, since He is Lord of heaven and earth, does not dwell in temples made with hands. 25 Nor is He worshiped with men's hands, as though He needed anything, since He gives to all life, breath, and all things. 26 And He has made from one blood every nation of men to dwell on all the face of the earth, and has determined their pre-appointed times and the boundaries of their dwellings, 27 so that they should seek the Lord, in the hope that they might grope for Him and find Him, though He is not far from each one of us;
Rev 3:20 - Behold, I stand at the door and knock. If anyone hears My voice and opens the door, I will come in to him and dine with him, and he with Me.
(DG) What is blasphemy against the Holy Spirit?
We understand this by first understanding what the ministry of the Holy Spirit is all about. Jesus said, and when He has come, He will convict the world of sin, and of righteousness, and of judgment (John 16:8); and that He will testify of Me (John 15:26). Therefore, when we persistently reject the work the Holy Spirit wants to do in us, when we have a continued, settled rejection of what He wants to tell us about Jesus, then we have blasphemed the Holy Spirit.
The blasphemy of the Holy Spirit will never be forgiven - not because it is a sin "too big" for God to forgive, but because it is an attitude of heart that cares nothing for God’s forgiveness. It never has forgiveness because it never wants forgiveness God’s way. It may want forgiveness on its own terms, but never God’s way.
The way to not blaspheme the Holy Spirit is to receive Jesus Christ today, to stop rejecting His work of bringing you to Jesus.
God foreknew whether we choose Him or not.
1 Peter 1:2 - 1 Peter, an apostle of Jesus Christ, To the pilgrims of the Dispersion in Pontus, Galatia, Cappadocia, Asia, and Bithynia, 2 elect according to the foreknowledge of God the Father, in sanctification of the Spirit, for obedience and sprinkling of the blood of Jesus Christ: Grace to you and peace be multiplied.
So, God is giving one final opportunity in due time by convicting them through His Holy Spirit.
John 16:8,9 - 7 Nevertheless I tell you the truth. It is to your advantage that I go away; for if I do not go away, the Helper will not come to you; but if I depart, I will send Him to you. 8 And when He has come, He will convict the world of sin, and of righteousness, and of judgment: 9 of sin, because they do not believe in Me; 10 of righteousness, because I go to My Father and you see Me no more; 11 of judgment, because the ruler of this world is judged.
For some they believe Jesus or deny their self and choose God by their own free will and confess their sin and accept Jesus as their Savior.
Rom 10:9,10 - 9 that if you confess with your mouth the Lord Jesus and believe in your heart that God has raised Him from the dead, you will be saved. 10 For with the heart one believes unto righteousness, and with the mouth confession is made unto salvation.
For some even after His Holy Spirit's conviction instead of believe and confess they blaspheme against Holy Spirit by placing either themselves or others/created things in the place of God. From that point on God might honor their desires and give them debased mind. So, they will continue suppress the truth by their selfishness till their death
Rom 1:18-21 - 18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness, 19 because what may be known of God is manifest in them, for God has shown it to them. 20 For since the creation of the world His invisible attributes are clearly seen, being understood by the things that are made, even His eternal power and Godhead, so that they are without excuse, 21 because, although they knew God, they did not glorify Him as God, nor were thankful, but became futile in their thoughts, and their foolish hearts were darkened. 22 Professing to be wise, they became fools, 23 and changed the glory of the incorruptible God into an image made like corruptible man--and birds and four-footed animals and creeping things.
So, every unbeliever in Christ who goes to Hell might have blasphemed against the Holy Spirit at least once some point in time.
Is it ok to blaspheme Satan for what he does to us and how he trap us?
He is not a sacred or holy person to blaspheme him (read the meaning for blaspheme). But we may curse or blame him for the troubles/issues that he may cause. Also we do not want to follow his footsteps.
Not all the issues and problems in our lives are caused by him.
Some believers in Christ always blame Satan/evils spirit for all their problems/troubles/issues instead of realizing their own sins.
If we practice this then it will lead us to always blame others for our silly mistakes. It become our attitude and it keeps us in self righteousness.
If you closely notice in the above passages (Rev 16:9,11,21) Satan is training them to blaspheme God for all the issues and pain that they go through. This attitude never allow them to think of the repentance. Instead of repenting and seeking God's help they always stay in the self righteous state.
At the same time do not underestimate Satan's schemes, strategies towards believers in Christ. When we grow spiritually Satan will always look for opportunities to tempt, trap or devour us.
Luke 4:13 - Now when the devil had ended every temptation, he departed from Him until an opportune time
1 Peter 5:8 - Be sober, be vigilant; because your adversary the devil walks about like a roaring lion, seeking whom he may devour
Eph 6:10-11 - 10 Finally, my brethren, be strong in the Lord and in the power of His might. 11 Put on the whole armor of God, that you may be able to stand against the wiles (NIV: schemes, NLT: strategies and tricks) of the devil
How to identify and How to handle? or What we need to do?
Prayerfully discern this by the help of the Holy Spirit.
1 Cor 12:10 - 7 But the manifestation of the Spirit is given to each one for the profit of all: 8 for to one is given the word of wisdom through the Spirit, to another the word of knowledge through the same Spirit, 9 to another faith by the same Spirit, to another gifts of healings by the same Spirit, 10 to another the working of miracles, to another prophecy, to another discerning of spirits, to another different kinds of tongues, to another the interpretation of tongues. 11 But one and the same Spirit works all these things, distributing to each one individually as He wills.
If the Lord convicts us by gently pointing us that these issues/problems that we face are due to your sins then confess that to our Lord. May the God almighty cleanse us and strengthen us by filling us by His Holy Spirit.
1 John 1:9-10 - 9 If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness. 10 If we say that we have not sinned, we make Him a liar, and His word is not in us.
Otherwise if those issues/problems are caused by Satan then....
Draw near to God and resist the devil and he will flee.
James 4:7-8 - 7 Therefore submit to God. Resist the devil and he will flee from you. 8 Draw near to God and He will draw near to you. Cleanse your hands, you sinners; and purify your hearts, you double-minded.
1 Peter 5:9 - 8 Be sober, be vigilant; because your adversary the devil walks about like a roaring lion, seeking whom he may devour. 9 Resist him, steadfast in the faith, knowing that the same sufferings are experienced by your brotherhood in the world.
Eph 6:10-11 - 10 Finally, my brethren, be strong in the Lord and in the power of His might. 11 Put on the whole armor of God, that you may be able to stand against the wiles of the devil
Luke 4:1-7 - 1 Then Jesus, being filled with the Holy Spirit, returned from the Jordan and was led by the Spirit into the wilderness, 2 being tempted for forty days by the devil. And in those days He ate nothing, and afterward, when they had ended, He was hungry. 3 And the devil said to Him, "If You are the Son of God, command this stone to become bread." 4 But Jesus answered him, saying, "It is written, 'Man shall not live by bread alone, but by every word of God.' "5 Then the devil, taking Him up on a high mountain, showed Him all the kingdoms of the world in a moment of time. 6 And the devil said to Him, "All this authority I will give You, and their glory; for this has been delivered to me, and I give it to whomever I wish. 7 Therefore, if You will worship before me, all will be Yours." 8 And Jesus answered and said to him, "Get behind Me, Satan! For it is written, 'You shall worship the Lord your God, and Him only you shall serve.' " 9 Then he brought Him to Jerusalem, set Him on the pinnacle of the temple, and said to Him, "If You are the Son of God, throw Yourself down from here. 10 For it is written: 'He shall give His angels charge over you, To keep you,' 11 "and, 'In their hands they shall bear you up, Lest you dash your foot against a stone.' " 12 And Jesus answered and said to him, "It has been said, 'You shall not tempt the Lord your God.' " 13 Now when the devil had ended every temptation, he departed from Him until an opportune time.
Is it ok to rebuke the devil/Satan?
Sure it is ok to rebuke the devil/Satan if Holy Spirit leads.
Acts 13:10 - 6 Now when they had gone through the island to Paphos, they found a certain sorcerer, a false prophet, a Jew whose name was Bar-Jesus, 7 who was with the proconsul, Sergius Paulus, an intelligent man. This man called for Barnabas and Saul and sought to hear the word of God. 8 But Elymas the sorcerer (for so his name is translated) withstood them, seeking to turn the proconsul away from the faith. 9 Then Saul, who also is called Paul, filled with the Holy Spirit, looked intently at him 10 and said, "O full of all deceit and all fraud, you son of the devil, you enemy of all righteousness, will you not cease perverting the straight ways of the Lord? 11 And now, indeed, the hand of the Lord is upon you, and you shall be blind, not seeing the sun for a time." And immediately a dark mist fell on him, and he went around seeking someone to lead him by the hand.
Acts 16:18- 16 Now it happened, as we went to prayer, that a certain slave girl possessed with a spirit of divination met us, who brought her masters much profit by fortune-telling. 17 This girl followed Paul and us, and cried out, saying, "These men are the servants of the Most High God, who proclaim to us the way of salvation." 18 And this she did for many days. But Paul, greatly annoyed, turned and said to the spirit, "I command you in the name of Jesus Christ to come out of her." And he came out that very hour. 19 But when her masters saw that their hope of profit was gone, they seized Paul and Silas and dragged them into the marketplace to the authorities.
Warning: Acts 19:16 - 11 Now God worked unusual miracles by the hands of Paul, 12 so that even handkerchiefs or aprons were brought from his body to the sick, and the diseases left them and the evil spirits went out of them. 13 Then some of the itinerant Jewish exorcists took it upon themselves to call the name of the Lord Jesus over those who had evil spirits, saying, "We exorcise you by the Jesus whom Paul preaches." 14 Also there were seven sons of Sceva, a Jewish chief priest, who did so. 15 And the evil spirit answered and said, "Jesus I know, and Paul I know; but who are you?" 16 Then the man in whom the evil spirit was leaped on them, overpowered them, and prevailed against them, so that they fled out of that house naked and wounded. 17 This became known both to all Jews and Greeks dwelling in Ephesus; and fear fell on them all, and the name of the Lord Jesus was magnified. 18 And many who had believed came confessing and telling their deeds.
Allow God to rebuke him if Holy Spirit didn't lead you to rebuke then . He is always available to help us.
Zec 3:2 - 1 Then he showed me Joshua the high priest standing before the Angel of the Lord, and Satan standing at his right hand to oppose him. 2 And the Lord said to Satan, "The Lord rebuke you, Satan! The Lord who has chosen Jerusalem rebuke you! Is this not a brand plucked from the fire?"
Jude 9 - Yet Michael the archangel, in contending with the devil, when he disputed about the body of Moses, dared not bring against him a reviling accusation, but said, "The Lord rebuke you!"
John 17:15 - (Jesus) I do not pray that You should take them out of the world, but that You should keep them from the evil one.
Luke 22:31-32 - 31 And the Lord said, "Simon, Simon! Indeed, Satan has asked for you, that he may sift you as wheat. 32 But I have prayed for you, that your faith should not fail; and when you have returned to Me, strengthen your brethren."