Let's be clear: the blasphemy against the Holy Spirit is not taking the Lord's name in vain. It is not getting mad at God and telling Him you wish things were different. It is not pledging allegiance to Satan or having an ungodly thought flicker across your mind.
Blasphemy against the Holy Spirit - What is it?
Mark 3:20-30 and Matthew 12:22-32 tell us about blasphemy against the Holy Spirit. Jesus had cast a demon out of a blind and mute man. Not understanding that their Messiah stood before their very eyes, the Pharisees declared that the power Jesus used to cast out the demon must have come from Satan. Jesus explained that any sin or blasphemy, even against He, Himself, could be forgiven. Blasphemy against the Holy Spirit, however, can't be forgiven. The Pharisees had attributed the work of the Holy Spirit to Satan. They claimed that Jesus was demon-possessed, not Spirit-filled. They intentionally rejected the prophecies of the Old Testament and attributed the Spirit's work to Satan.
This aspect of blasphemy against the Holy Spirit cannot happen today. Jesus is in heaven so we cannot watch Him perform a miracle and claim it was done in Satan's power. What we can do is continually refuse to believe the Holy Spirit when He testifies in our hearts the truth about Jesus Christ. Jesus is God (John 10:30). He died, was buried, and rose again for our sins (1 Corinthians 15:3-4). And Jesus is the only way for us to reconcile with God (John 14:6). To refuse to believe this is blasphemy against the Holy Spirit today, and God cannot forgive someone who dies in this sin. If we die, having continued to blaspheme against the Holy Spirit's promptings by rejecting these truths, we cannot be forgiven. This is the unpardonable sin—the only sin that will keep us from receiving forgiveness from God and going to heaven.
Is there an unpardonable sin? What is it?
Who is the Holy Spirit?
What is the role of the Holy Spirit? How is the Holy Spirit active in our lives today?
When do we receive the Holy Spirit?
What does it mean to be filled with the Holy Spirit?
Truth about the Holy Spirit