Much confusion abounds in connection with "the sin against the Holy Spirit". The general idea is that it will not be forgiven, for all eternity. This is supposed to be the message of Matthew 12:31,32 (and parallel to it: Mark 3:28-30 and Luke 12:10). There are many Christians who fear they have committed this sin and consider themselves, now, to be a hopeless case. This is extremely tragic.
How is that to be dealt with? What is the true meaning of these Scriptures? Here are a few points, in sequence.
Jesus had freed a man, who was possessed, from his bondage and had cured his blindness and dumbness (12:22). While the people were beside themselves with amazement, the Pharisees said: This man drives out demons by Beelzebub, the prince of the demons (12:24). In response, Jesus makes clear that this is an absurd accusation, because then it would be the opponent driving out the opponent, and thus, he would be divided against himself (12:25,26). What the Pharisees were saying, was not only a blasphemy against the Son of Man; from that, one can come back. But they blasphemed the Spirit of God by whom Jesus performed this miracle (12:28). Please note: they knew that God's Spirit was at work, otherwise one cannot blaspheme the Spirit. So it is not, "the sin against the holy Spirit," as it is commonly called, but "the blasphemy of the Spirit" (12:31). I.e., knowing that the Spirit of God performed a miracle, but attributing this to satan. No additional miracle would convince the Pharisees, and that is why Jesus said that this blasphemy will not be forgiven, "neither in this eon nor in the eon to come" (:32). These people would not repent and, therefore, there would be no forgiveness for them.
Are these Pharisees thus hopelessly lost? No, they are lost for "this eon and for the one to come." That is what Jesus said. No less, but no more, either. Do not subtract from it, but neither add anything to it. The coming eon is certainly not the last eon. Paul speaks of "the coming eonS" (Ephesians 2:7). And the Scripture says that Christ will reign "until the eons of the eons" (Rev.11:15). Unfortunately and utterly incorrectly, this is translated: "for ever and ever". One thing is certain: Christ will not reign endlessly. His last act of rulership is to abolish death, which means to make all mankind to have life beyond the reach of death (1Cor.15:22-28). The knees of these unrepentant Pharisees will bend and they will realize and acknowledge that Jesus is Lord, to the glory of God, the Father (Phil.2:9-11). Very significantly, no man can realize and acknowledge this, except by the Spirit of God (1Cor.12:3).
It is the climax of deception what the translators have done in Mark 3:29:
But he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation:
To stay with the terminology: this is an unforgivable error! This is not a translation, but bad theology. Here, there it is not a question of "eternity" but of "eon", the same word as in Mat.12:32. And it is not "eternal", but an eonian sin, a sin that is related to this and to the coming eon. That makes the story completely different!
Nobody needs to worry about having committed "the blasphemy of the Spirit", for such an anxiety proves that one is not a slanderer. In the second place, we do not live in the time that the Spirit of God manifests itself, as when Jesus performed this miracle. No one can blaspheme such activities. And most importantly: also they (who will miss out on the future eons) are not hopelessly lost, because the living God IS the Savior of all mankind; so also of them!
Translation: Peter Feddema