On The Holy Trinity by St. Augustine
Chapter 15.--Of the Same Subject.
19. It is not then difficult to see that the devil was conquered, when he who was slain by Him rose again. It is something more, and more profound of comprehension, to see that the devil was conquered when he thought himself to have conquered, that is, when Christ was slain. For then that blood, since it was His who had no sin at all, was poured out for the remission of our sins; that, because the devil deservedly held those whom, as guilty of sin, he bound by the condition of death, he might deservedly loose them through Him, whom, as guilty of no sin, the punishment of death undeservedly affected. The strong man was conquered by this righteousness, and bound with this chain, that his vessels might be spoiled, which with himself and his angels had been vessels of wrath while with him, and might be turned into vessels of mercy. For the Apostle Paul tells us, that these words of our Lord Jesus Christ Himself were spoken from heaven to him when he was first called. For among the other things which he heard, he speaks also of this as said to him thus: |For I have appeared unto thee for this purpose, to make thee a minister and a witness both of these things which thou hast seen from me, and of those things in the which I will appear unto thee; delivering thee from the people, and from the Gentiles, unto whom now I send thee, to open the eyes of the blind, and to turn them from darkness [to light], and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified, and faith that is in me.| And hence the same apostle also, exhorting believers to the giving of thanks to God the Father, says: |Who hath delivered us from the power of darkness and hath translated us into the kingdom of His dear Son: in whom we have redemption, even the forgiveness of sins.| In this redemption, the blood of Christ was given, as it were, as a price for us, by accepting which the devil was not enriched, but bound: that we might be loosened from his bonds, and that he might not with himself involve in the meshes of sins, and so deliver to the destruction of the second and eternal death, any one of those whom Christ, free from all debt, had redeemed by pouring out His own blood unindebtedly; but that they who belong to the grace of Christ, foreknown, and predestinated, and elected before the foundation of the world should only so far die as Christ Himself died for them, i.e. only by the death of the flesh, not of the spirit.