If there was a person who was going to blaspheme the Holy Ghost ONLY if you told exactly how to commit this sin, would you still tell them how to do it?
What exactly would be your response to this question? What exactly would you do in this scenario?
Someone with that mindset is likely already in the process of doing it anyway, regardless of whether they are told an explanation of what it means. That's because the blasphemy against the Holy Spirit is a life-long knowing and active rejection of forgiveness. That is to say, the reason why it is called an "unpardonable sin" is neither because God is unable or unwilling to forgive it; but because the one committing it is themselves firmly opposed to being forgiven.
The warning Jesus gives isn't because his accusers were already guilty of it, but rather it served as a warning so that they should not be found guilty of it in the future. For they blasphemed Christ by accusing Him of casting out demons by the power of demons, so He says that blasphemy against the Son is forgiven. He then warns them, however, against blasphemy against the Spirit--for if they continue in their current trajectory, beholding the works of God plain and obvious to them, but denying it out of their own fleshly desire, thereby resisting and rejecting the Spirit's work to lead them to contrition and repentance and a confession of the truth, they shall find that there is no forgiveness for they have made their whole selves opponents of forgiveness.
A dying man who fights against doctors and paramedics trying to save him, cursing them, spitting out medicine, swatting them away and fighting them as they try to save his life will die. It has nothing to do with whether the doctors and paramedics could or wanted to save him--of course they did, they are actively fighting to save his life--but the whole time he is doing everything he can to refuse to be saved and thus succumbs to death.
It is only the Holy Spirit who can take us, sinners who are at enmity against God, and give us faith and melt the stony heart, and bring us to contrition and penitential grief. For through the Law we are condemned guilty; but it is through the Gospel that we are declared righteous for Christ's sake and on Christ's account, declared forgiven, and our guilt wrested away from us by the soothing peace of the Good News.
Whether one knows, or doesn't know, the meaning of Jesus' words and their implication and application won't lead them to this fate. However, for those who are worried and afraid, they can be assured of God's mercy in the Gospel; and thus knowing what Jesus said and why here is paramount--in order that they can be assured and have their souls soothed by the precious promises of God's grace and kindness: Their sins are forgiven, they have peace with God, and there is none outside of God's desire to save. God is at work to save, here and now, by His unceasing and abundant grace through the Gospel.
-CryptoLutheran
