Here is the comment from St. Ahtanasius from the Catena Aurena,
The ancients indeed, the learned Origen and the great Theognostus, describe this to be the blasphemy against the Holy Ghost, when they who have been counted worthy of the gift of the Holy Spirit in Baptism, fall back into sin. For they say that for this reason they can not obtain pardon; as Paul says, It is impossible for those who have been made partakers of the Holy Ghost to renew them again, &c.
But each adds his own explanation. For Origen gives this as his reason; God the Father indeed penetrates and contains all things, but the power of the Son extends to rational things only; the Holy Spirit is only in those who partake of Him in the gift of Baptism. When then catechumens and heathens sin, they sin against the Son who abides in them, yet they may obtain pardon when they become worthy of the gift of regeneration. But when the baptized commit sin, he says that their offense touches the Spirit, after coming to whom they have sinned, and therefore their condemnation must be irrevocable.
But Theognostus says, that he who has gone beyond both the first and second threshold deserves less punishment, but he who has also passed the third, shall no more receive pardon. By the first and second threshold, he speaks of the doctrine of the Father and the Son, but by the third the partaking of the Holy Spirit. According to St. John, When the Spirit of truth is come, he will lead you into all truth. Not as though the doctrine of the Spirit was above that of the Son, but because the Son condescends to those who are imperfect, but the Spirit is the seal of those who are perfect. If then not because the Spirit is above the Son, blasphemy against the Spirit is unpardonable; but because remission of sin is indeed to the imperfect, but no excuse remains to the perfect, therefore since the Son is in the Father, He is in those in whom the Father and the Spirit are not absent, for the Holy Trinity cannot be divided. Besides this, if all things were made by the Son, and all things consist in Him, He will Himself be truly in all; so that it must needs be, that he who sins against the Son, sins against the Father also, and against the Holy Spirit. But holy Baptism is given in the name of the Father, and the Son, and the Holy Spirit. And so they that sin after baptism commit blasphemy against the holy Trinity. But if the Pharisees had not received baptism, how did He condemn them as if they had spoken blasphemy against the Holy Spirit, of which they were not yet partakers, especially since He did not accuse them simply of sin, but of blasphemy? But these differ, for he who sins transgresses the Law, but he who blasphemes offends against the Deity Himself. But again, if to those who sin after baptism there is no remission of the punishment of their offenses, how does the Apostle pardon the penitent at Corinth; but he travails in birth of the backsliding Galatians until Christ be formed again in them.
