Therefore, whoever is guilty of impenitence against the Spirit, in which the unity and society of the church's communion are gathered, will never be forgiven; because he has closed himself off from what forgives; and he will deservedly be condemned with the spirit that is divided against itself, and he is also divided against the Holy Spirit who is not divided against Himself. The very testimonies of the gospel warn us of this, if we scrutinize them carefully. For according to Luke, the Lord does not say this where He responded to those who said that He casts out demons by the prince of demons, that it will not be forgiven to the one who blasphemes against the Holy Spirit. Hence it is clear, that this was not said only once by the Lord. But also it should not be negligently overlooked where it was said. For He was speaking of those who confessed Him or denied Him before men, where He said: But I say to you, Whoever confesses Me before men, the Son of Man will also confess him before the angels of God; but whoever denies Me before men will be denied before the angels of God. And so that the salvation of the apostle Peter, who denied Him three times before men, might not be despaired of, He immediately added: And everyone who speaks a word against the Son of Man will be forgiven; but the one who blasphemes against the Holy Spirit will not be forgiven. This is, indeed, the blasphemy of the impenitent heart, which resists the forgiveness of sins, which happens in the Church through the Holy Spirit. Peter did not have this blasphemy, whom soon repented when he wept bitterly, and, having overcome the spirit which was divided against itself, and which had asked for him to be tormented, against which the Lord prayed for him, so that his faith would not fail, he received even the Holy Spirit, to whom he did not resist, so that not only his sin would be forgiven, but through him, the forgiveness of sins would be preached and given.
From the other two Evangelists, the same is implied.
Among the other two Evangelists, the cause for the statement about the blasphemy of the Spirit being made was the mention of the unclean spirit which is divided against itself. For it had been said about the Lord that He cast out demons by the prince of demons; there the Lord said that He casts out demons by the Holy Spirit, so that the Spirit, who is not divided against Himself, may overcome and cast out the one who is divided against himself; but that man remains in his perdition, who refuses to pass into the peace of Him who is not divided against Himself through unrepentance. For Mark narrates it thus: "Verily I say unto you, all sins shall be forgiven unto men and blasphemies whatsoever they shall blaspheme; but he that shall blaspheme against the Holy Spirit hath never forgiveness, but is in danger of eternal damnation." After these words of the Lord, he then added, saying: "Because they said he hath an unclean spirit," to show that this was the cause for His statement, since they had said He cast out demons by Beelzebub, the prince of the demons. Not that there is a blasphemy that is not forgiven, since even this shall be forgiven if proper repentance follows; but that, as I said, the cause was the mention of the unclean spirit, which the Lord showed to be divided against itself, because of the Holy Spirit, who is not only not divided against Himself but also makes those indivisible whom He gathers, forgiving sins that are divided against themselves and dwelling in the cleansed; so that it may be, as it is written in the Acts of the Apostles, "the multitude of them that believed were of one heart and of one soul." This gift of forgiveness is resisted only by one who has the hardness of an unrepentant heart. For in another passage the Jews also said about the Lord that He had a demon; yet there He said nothing about the blasphemy of the Holy Spirit: because they did not so object to an unclean spirit, that could be shown to be divided against itself from their speech, as Beelzebub by whom they said He was casting out demons.
To resist the unity of the Church with an impenitent heart is an unforgivable blasphemy.
In this particular reading according to Matthew, the Lord revealed much more clearly what he wished to be understood here; that is, that he who speaks a word against the Holy Spirit resists the unity of the Church with an unrepentant heart, wherein the forgiveness of sins is performed by the Holy Spirit. For, as has already been said, those who, although carrying and handling the sacraments of Christ, are separated from his congregation, do not have this Spirit. For where he spoke about the division of Satan against Satan, and that he himself cast out demons in the Holy Spirit, certainly in the Spirit who is not against himself, as he is divided; there immediately, lest anyone might think, through those who under the name of Christ gather conventicles outside of his flock, that even the kingdom of Christ is divided against itself: He said, "He who is not with me is against me; and he who does not gather with me, scatters"; to show that those who prefer to gather outside, do not gather but scatter. Then he added: "Therefore I say to you: Every sin and blasphemy will be forgiven to men; but blasphemy against the Spirit will not be forgiven." What is this? Therefore, is the blasphemy against the Spirit unforgivable because he who is not with Christ is against him; and he who does not gather with him, scatters? Indeed, truly. For he who does not gather with him, however he may gather under his name, does not have the Holy Spirit.
Congregations outside the Church do not have the Holy Spirit by which sins are forgiven.
Here absolutely, here we are compelled to understand that the remission of all sins and all blasphemy can only be possible in the congregation of Christ, which does not scatter. For it is gathered in the Holy Spirit, who is not divided against himself, unlike that unclean spirit. And therefore, all congregations, or rather dispersions, which call themselves churches of Christ, and are divided among themselves and contrary to each other, and hostile to the gathering in unity which is the true Church of Christ, do not pertain to his congregation just because they seem to bear its name. However, they would pertain if the Holy Spirit, in whom this congregation is united, were divided against himself. But since this is not so (for whoever is not with Christ is against him; and whoever does not gather with him, scatters), therefore every sin and blasphemy will be forgiven to men in this congregation, which Christ gathers in the Holy Spirit and not divided against himself; however, the blasphemy against the Spirit, which consists in resisting this great gift of God with an unrepentant heart until the end of this life, will not be forgiven. For if anyone is so opposed to the truth that he resists God speaking not through the Prophets but in his only Son (since for our sake he willed to be the Son of Man to speak to us in him), it will be forgiven him when he repents and turns to the kindness of God, who, since he wills not the death of the wicked as much as their return and life, gave the Holy Spirit to his Church, so that to whomever it forgives sins in him, they are forgiven. But whoever is an enemy of this gift, so as not to seek it through repentance but to resist it through impenitence, makes unforgivable not any sin, but the very remission of sins being despised or even opposed. Thus it is said to speak against the Holy Spirit when one never comes from dispersion to the congregation which has received the Holy Spirit for the remission of sins. Even if someone comes to this congregation through an evil but nonetheless catholic minister, reproachable and fictitious, with a sincere heart, he receives the remission of sins in the Holy Spirit. This Spirit operates in the holy Church even at this time when it is being threshed like a threshing floor with chaff, in such a way that he does not despise anyone’s true confession, nor is he deceived by anyone’s dissimulation; and thus he shuns the reprobates but also gathers the upright through their ministry. Therefore, the only refuge to avoid irremissible blasphemy is to beware of an unrepentant heart; nor should repentance be believed to avail otherwise than by holding to the Church where the remission of sins is given and the fellowship of the Spirit is preserved in the bond of peace.
Conclusion.
As best I could, I have addressed a most difficult question, if at all I could, with the Lord having mercy and aiding me. Whatever, however, in its difficulty I have not been able to grasp, let it not be imputed to the truth itself, which beneficially challenges the devout even when it is hidden, but to my weakness, for I have been unable either to perceive what should be understood or to explain what has been understood. However, regarding those things that we perhaps have been able to investigate by thinking and to resolve by speaking, thanks are to be given to Him from whom we sought, from whom we asked, to whom we knocked, so that we might have from where we might be nourished by meditating, and supply to you by speaking.