It is often maintained that the “unpardonable sin” is when someone “rejects Jesus Christ as Lord and Savior.” However, Mark 3:30 defines exactly what the sin is. The scribes said that Jesus did His miracles by an “unclean spirit,” attributing the work of the Holy Spirit to Satan’s power. (In Matt. 12:28, Jesus clearly identifies who is doing the work by saying that He “cast out demons by the Spirit of God.”) If sinners do not acknowledge the Holy Spirit’s work in their lives as being from God, they cannot be saved and enter the kingdom of God.
It is only by the Holy Spirit that men are convicted of their sin and need for righteousness (John 16:8), and it is only by the Holy Spirit that anyone can discern spiritual truths and understand the salvation God offers in Christ (1 Cor. 2:12–14). Therefore, those who are “stiff-necked” and who “always resist the Holy Spirit” (Acts 7:51) will die in their sins. Because they refuse to acknowledge their sin, they refuse to repent and trust the Savior. For this reason, anyone who rejects the Holy Spirit’s convicting influence and does not repent will not be forgiven, “either in this age or in the age to come” (Matt. 12:32).
Mark 3:29 but he who blasphemes against the Holy Spirit never has forgiveness, but is subject to eternal condemnation”