Matthew 12:31-32 / Mark 3:28-30…
Many people have grieved over the idea that they may be guilty of this sin. What is the unforgiveable sin? It is to blaspheme the Holy Spirit. The immediate context was that they kept saying that what Jesus did was done by an evil spirit or a demon rather than by the Spirit of God. It was not some one-time event; it was an ongoing, willful rejection of Christ, the continual hardening of their hearts. The blasphemy of the Holy Spirit is called the “unforgivable sin” because it is rejecting Jesus and His offer of forgiveness. So Jesus here warns the religious leaders about the consequences of rejecting Him; it would be an unforgivable sin.
The question then becomes whether or not it is possible to commit the unforgiveable sin today, or could this particular sin only have occurred in Jesus’ day? The truth is that the final, full, willful rejection of Jesus still happens. However, the fact that the believer worries about this sin is evidence that the true believer could not commit this sin. The one who commits the sin is the very one who doesn’t even care if he has. That is the point; they don’t feel the need to be forgiven, and so they won’t be.
To blaspheme the Spirit means to give up on Jesus, to say that He isn’t God, that He isn’t the only way to the Father. It means to believe that what He did and is doing is not right and just. In other words, it is to finally reject the very things the Holy Spirit brings, the conviction of sin, righteousness, and judgment (John 16:7-11). To reject that is to reject forgiveness, and that is unforgivable. But if you want to be forgiven, then it is the Holy Spirit who is moving you to that, and that is not blasphemy. No sin is unforgiveable if you want to be forgiven.