That the Spirit forgives sin is common to Him with the Father and the Son, but not with the Angels.
112. Tell me, then, whoever you are who deny the Godhead of the Holy Spirit. The Spirit could not be liable to sin, Who rather forgives sin. Does an Angel forgive? Does an Archangel? Certainly not, but the Father alone, the Son alone, and the Holy Spirit alone. Now no one is unable to avoid that which he has power to forgive.
113. But perhaps some one will say that the Seraph said to Isaiah: “Behold, this hath touched thy lips, and shall take away thine iniquities, and purge away thy sins.”144 Is. vi. 7. Shall take away, he says, and shall purge, not I will take away, but that fire from the altar of God, that is, the grace of the Spirit. For what else can we piously understand to be on the altar of God but the grace of the Spirit? Certainly not the wood of the forests, nor the soot and coals. Or what is so in accordance with piety as to understand according to the mystery that it was revealed by the mouth of Isaiah that all men should be cleansed by the passion of Christ, Who as a coal according to the flesh burnt up our sins, as you read in Zechariah: “Is not this a brand cast forth from the fire? And that was Joshua clothed in filthy garments.”145 Zech. iii. 2, 3.
114. Lastly, that we may know that this mystery of the common redemption was most clearly revealed by the prophets, you have also in this place: “Lo, it hath taken away thy sins;”146 Ibid. 4. not that Christ put aside His sins Who did no sin, but that in the flesh of Christ the whole human race should be loosed from their sins.
115. But even if the Seraph had taken away sin, it would have been as one of the ministers of God appointed to this mystery. For thus said Isaiah: “For one of the Seraphim was sent to me.”147 Is. vi. 6.
CAPUT X.
Quod Spiritus peccata condonat, hoc illi cum Patre ac Filio, non autem cum angelis esse commune.
112. [Alias cap. IX.] Dic igitur, quicumque Spiritus sancti divinitatem negas: Spiritus autem obnoxius non potuit esse peccato, qui magis peccata condonat. Numquid angelus donat? numquid archangelus? Non utique, sed donat solus Pater, solus 0731B Filius, solus Spiritus sanctus (Luc. V, 21). Nemo autem quod potest donare, non potest evitare.
113. Sed fortasse dixit aliquis quia et Seraphim dixit Esaiae: Ecce tetigit hoc labia tua, et auferet iniquitates tuas, et peccata tua circumpurgabit (Esai. VI, 7). 624 Auferet, inquit, et circumpurgabit: non ego auferam, sed ignis ille de altari Dei, hoc est, gratia spiritalis. Quid enim aliud pie intelligere possumus in altari Dei esse, nisi Spiritus gratiam? Non utique lignum silvarum, nec fuliginem atque carbonem. Aut quid tam pium, quam ut secundum mysterium intelligamus quia revelabatur in ore Esaiae omnes homines per passionem Christi esse purgandos, qui velut carbo secundum carnem exussit nostra peccata, sicut in Zacharia habes: Nonne hic titio ejectus 0731C ab igni? Et ille erat Jesus indutus estimenta sordida (Zach. III, 2, 3).
114. Denique ut sciamus communis hoc redemptionis mysterium per prophetas evidentissime revelatum, etiam hoc loco habes dictum: Ecce abstulit peccata tua (Ibid., 4): non quod Christus peccata sua deponeret, qui peccatum non fecit; sed quod in carne Christi omne a peccatis suis genus absolveretur humanum.
115. Sed etiamsi Seraphim abstulisset peccatum, quasi unum utique de ministris Dei ad hoc esset mysterium destinatum. Sic enim dixit Esaias: Quia missum est ad me unum de Seraphim (Esai. VI, 6).