St. Matthew 12.vv.22-32
~ They brought Jesus a demoniac who was blind and mute; and he cured him, so that the one who had been blind and mute could speak and see. All the crowds were amazed and said, "Can this be the Son of David?". But when the Pharisees heard it, they said, "It is only by Beelzebub, the ruler of demons, that this fellow casts out the demons". He knew what they were thinking and said to them, "Every kingdom divided against itself is laid waste, and no city or house divided against itself will stand. If Satan casts out Satan, he is divided against himself; how then will his kingdom stand? It I cast out demons by Beelzebub, by whom do your own exorcists cast them out? therefore they will be your judges. But if it is by the Spirit of God that I cast out demons, then the kingdom of God has come to you. Or how can one enter a strong man's house and plunder his property, without first tying up the strong man? Then indeed the house can be plundered. Whoever is not with me is against me, and whoever does not gather with me scatters. Therefore I tell you, people will be forgiven for every sin and blasphemy, but blasphemy against the Spirit will not be forgiven. Whoever speaks a word against the Son of Man will be forgiven, but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come". ~
At the close of this passage there is a statement by Jesus which has caused a great deal of heart-searching and, indeed, anxiety to those who do not fully understand it. I refer to the "Unforgivable Sin". As Christians we naturally assume (and rightly so) that there is no sin so grievous that God will not forgive it - but we must always remember that God is the one who forgives the sins of "all them that are penitent" and herein is the problem and the answer. Can God possibly or reasonably forgive the sins of those who are not conscious of sin, who do not show remorse for wrong doing, who do not sue for mercy, pardon and peace? It has been said that those who believe they have committed the "unforgivable sin" should be assured that they have not committed it. This may be an over-simplification of the case; but it is true nevertheless.
As a layman, before entering the Ordained Ministry, I used to visit the local prison regularly at least once a week in the evening after work. I was privileged to receive a cell key and to visit freely the prisoners under the Rule 43 category, that is, those who for murder, child abuse or other serious crimes, were shut up for most of the day in their cells for their own protection from other prisoners who might assault them. As a layman, and not a priest, I found that prisoners spoke very readily of their problems. I never probed into their affairs, but often they spoke of their fears that they could never be forgiven their sins (and crimes). To me this was a source of considerable concern, for it was clear that (and I blame them not) they had totally misunderstood the teaching of Jesus about forgiveness. This was a "heaven-sent" opportunity to stress that only if their hearts were hardened so that they felt no remorse or sense of guilt, and only if they persisted in self-justification and resisted the invitation of Christ to confess their sins and receive pardon and peace - only so could they possibly be said to have committed a sin which cannot be forgiven. God does not compel us to confess our sins, nor can he forgive sins that we do not acknowledge.
It is unfortunate (to say the least) that the word "repent" is so often used in a negative sense, that is, in repining, making oneself miserable with the memory of past wrongdoing, instead of grasping the opportunity of renewal offered to us in God's forgiveness of our sins. Repentance or "metanoia" involves a positive dynamic, a radical renewal of heart, mind, soul, of way of life, of relationship with God, others and ourselves.
Not only does forgiveness accepted bring pardon and peace to those who receive it from Christ, but casebooks of doctors, psychologists and psychiatrists recount numerous cases of those who, receiving forgiveness from God and their fellows, have gained physical healing when their feelings of anxiety and guilt have been allayed and they have gained that sense of pardon and peace that God wills for all his children - the peace that passes all understanding.
The "unforgivable sin" is a persistent and hardened rejection of the proffered love of God and his forgiveness, a wilful refusal to acknowledge guilt and to accept the gift of pardon which God in his grace offers to us.