Is it possible for believers to commit blaspheme of the Holy Spirit and commit an unpardonable sin?
God’s Holy Name
God’s name is holy and to be treated with great reverence and respect. God took His name so seriously that one of the laws in the Old Testament said, “Whoever blasphemes the name of the Lord shall surely be put to death. All the congregation shall stone him. The sojourner as well as the native, when he blasphemes the Name, shall be put to death” (Lev 24:11). Blaspheme means to speak irreverently about God or speak evil about sacred things, including uttering profanities, and if you did that in the Old Testament, your life was about to end, but ancient Israel blasphemed God’s good name by the way they disobeyed God and fell into idolatry. Ezekiel wrote, “Thus says the Lord God: In this also your fathers blasphemed me, by dealing treacherously with me” (Ezk 20:27b), which means that it wasn’t long before ancient Israel began to worship other gods, which are no gods at all. They began to worship metal images, stone carvings, and wooden deities. In other words, they began to worship the creation instead of the Creator. The Apostle Paul wrote that even in his day, “they exchanged the truth about God for a lie and worshiped and served the creature rather than the Creator, who is blessed forever” (Rom 1:25).
Conduct and Blaspheme
Shortly after David committed adultery and murder through conspiracy, Nathan the Prophet came to confront him with these sins. That’s when “David said to Nathan, “I have sinned against the Lord.” And Nathan said to David, “The Lord also has taken away your sin; you shall not die. However, because by this deed you have given occasion to the enemies of the Lord to blaspheme, the child also that is born to you shall surely die” (2 Sam 12:13-14; NASB). David’s acts as king of Israel tarnished God’s good name before the pagan nations, and God considers that blaspheme His name. Even in Rome, the same issue was prevalent as Paul wrote that “The name of God is blasphemed among the Gentiles because of you” (Rom 2:24). Apparently their conduct before unbelievers was bringing shame to the cause of Christ. They were blaspheming the name of Christ by identifying with the name of Christ but not living like Christ. Even worse, they were even “breaking the law” (Rom 2:23).
Blaspheme of the Spirit
Jesus, in speaking to the scribes, said that “all sins will be forgiven the children of man, and whatever blasphemies they utter, but whoever blasphemes against the Holy Spirit never has forgiveness, but is guilty of an eternal sin” (Mark 3:28-29), but why would Jesus say such a thing? Aren’t all sins covered by the blood of Christ? Why would Jesus give one of the most serious warnings in the Bible to the scribes? For one thing, “they were saying, “He has an unclean spirit” (Mark 3:30), or accusing Jesus’ miraculous powers as being from Satan. The scribes knew the Scriptures; they knew what the Messiah would do; they knew the prophecies He would fulfill, and they knew the miracles that would come, so they were without excuse. They knew the Scriptures and yet accused Jesus of doing miracles by the power of Satan. They were blaspheming God the Holy Spirit, because remember, blaspheming means to speak irreverently about God or sacred things, and that’s just what they’d done.
Blaspheme by Partiality
It must have grieved Paul’s heart to write about those who rejected the grace of God, and “By rejecting this, some have made shipwreck of their faith, among whom are Hymenaeus and Alexander, whom I have handed over to Satan that they may learn not to blaspheme” (1 Tim 1:19-20). James saw blaspheming God’s name as being partial to the rich and discriminating against the poor. He wrote that “you have dishonored the poor man. Are not the rich the ones who oppress you, and the ones who drag you into court? Are they not the ones who blaspheme the honorable name by which you were called? If you really fulfill the royal law according to the Scripture, “You shall love your neighbor as yourself,” you are doing well” (James 2:6-8). If we show partiality because someone has money, power, or influence, then we’re sinning because we are esteeming someone else better than others, when we’re told to esteem others better than ourselves (Phil 2:3).
A person who feels they’ve committed blaspheme against the Holy Spirit, and thereby has committed the unforgiveable sin, has probably not committed it. A person who’s heart is hardened would not even care if they’ve sinned or not, but a person who sees their own sinfulness shows repentance in their actions. An unsaved person doesn’t want to repent because they see no problem with what they’re doing. They might have worldly sorrow for what they’ve done or sorry for getting caught, but that kind of sorry does not bring godly repentance; it only brings death (2 Cor 7:10). If you’re worried you’ve committed the unpardonable sin, then I believe you haven’t done it. Having satanic thoughts and thinking evil things for a moment is not blaspheming God. That might only mean you’re under spiritual attack. I get some of the most hideous thoughts at times when I’m praying, and I’m sure it’s not from God, but those hideous thoughts do not mean I am blaspheming the Holy Spirit or that I’m attributing Jesus’ miracles to Satan. Believers just don’t do that. We attribute the miracles to the power of God and always for the glory of God.
Here is some related reading for you: What is the Unforgiveable Sin? A Biblical Analysis 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), Crossway Bibles. (2007). ESV: Study Bible: English standard version. Wheaton, Ill: Crossway Bibles. Used by permission. All rights reserved.