True Blasphemy
The Blasphemy of the Holy Spirit is to repent of God, and therefore to choose sin. The guilt of the Pharisees was a type of the false religious traditionalists, who though they claimed to reverence God and His law, outright rejected the Father through their actions against the Son, and literally cast out the Word of God to preserve their traditions.
As it was in the days of Christ, so shall it be in the last days concerning the church (the Body of Christ). Hence Christ's warnings to the Apostles that they too would be cast out, persecuted, and executed by those who made a pretense in following God, but had no true fellowship with Him.
The unforgivable sin is not an act which can be committed unintentionally or unknowingly; it is willful rebellion and apostasy against God in full (Through our failure in the law we have already blasphemed the Father, through our crucifixion of Christ have we blasphemed the Son, if now we blaspheme the Holy Spirit there is no more redemption and reconciliation and salvation, for we have refused every aspect of God, who is the only one capable of such things).
Rather the unforgivable sin is upon spiritual and supernatural evidence to deny what God has accomplished through His Word and Spirit. It is to purposefully be made in to a false witness (or better said, a liar and a direct contradiction to the example of Christ, the Word of God, which is truth itself) against God and His ministry by failing to truthfully testify of what God has done in your life and in the world.
For it is impossible for those who were once enlightened, and have tasted of the heavenly gift, and were made partakers of the Holy Ghost, And have tasted the good word of God, and the powers of the world to come, If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of God afresh, and put him to an open shame. For the earth which drinketh in the rain that cometh oft upon it, and bringeth forth herbs meet for them by whom it is dressed, receiveth blessing from God: But that which beareth thorns and briers is rejected, and is nigh unto cursing; whose end is to be burned. But, beloved, we are persuaded better things of you, and things that accompany salvation, though we thus speak. For God is not unrighteous to forget your work and labour of love, which ye have shewed toward his name, in that ye have ministered to the saints, and do minister. And we desire that every one of you do shew the same diligence to the full assurance of hope unto the end: That ye be not slothful, but followers of them who through faith and patience inherit the promises.
(Heb 6:4-12)
These things I command you, that ye love one another. If the world hate you, ye know that it hated me before it hated you. If ye were of the world, the world would love his own: but because ye are not of the world, but I have chosen you out of the world, therefore the world hateth you. Remember the word that I said unto you, The servant is not greater than his lord. If they have persecuted me, they will also persecute you; if they have kept my saying, they will keep yours also. But all these things will they do unto you for my name's sake, because they know not him that sent me. If I had not come and spoken unto them, they had not had sin: but now they have no cloke for their sin. He that hateth me hateth my Father also. If I had not done among them the works which none other man did, they had not had sin: but now have they both seen and hated both me and my Father. But this cometh to pass, that the word might be fulfilled that is written in their law, They hated me without a cause. But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me: And ye also shall bear witness, because ye have been with me from the beginning.
(Joh 15:17-27)
