Since, then, Christ's Passion was a sufficient and a superabundant atonement for the sin and the debt of the human race, it was as a price at the cost of which we were freed from both obligations. For the atonement by which one satisfies for self or another is called the price, by which he ransoms himself or someone else from sin and its penalty, according to Dan. 4:24: "Redeem thou thy sins with alms." Now Christ made satisfaction, not by giving money or anything of the sort, but by bestowing what was of greatest price—Himself—for us. And therefore Christ's Passion is called our redemption.
Reply Obj. 1: Man is said to belong to God in two ways. First of all, in so far as he comes under God's power: in which way he never ceased to belong to God; according to Dan. 4:22: "The Most High ruleth over the kingdom of men, and giveth it to whomsoever he will." Secondly, by being united to Him in charity, according to Rom. 8:9: "If any man have not the Spirit of Christ, he is none of His." In the first way, then, man never ceased to belong to God, but in the second way he did cease because of sin. And therefore in so far as he was delivered from sin by the satisfaction of Christ's Passion, he is said to be redeemed by the Passion of Christ.
Reply Obj. 2: Man by sinning became the bondsman both of God and of the devil. Through guilt he had offended God, and put himself under the devil by consenting to him; consequently he did not become God's servant on account of his guilt, but rather, by withdrawing from God's service, he, by God's just permission, fell under the devil's servitude on account of the offense perpetrated. But as to the penalty, man was chiefly bound to God as his sovereign judge, and to the devil as his torturer, according to Matt. 5:25: "Lest perhaps the adversary deliver thee to the judge, and the judge deliver thee to the officer"—that is, "to the relentless avenging angel," as Chrysostom says (Hom. xi). Consequently, although, after deceiving man, the devil, so far as in him lay, held him unjustly in bondage as to both sin and penalty, still it was just that man should suffer it, God so permitting it as to the sin and ordaining it as to the penalty. And therefore justice required man's redemption with regard to God, but not with regard to the devil.
Reply Obj. 3: Because, with regard to God, redemption was necessary for man's deliverance, but not with regard to the devil, the price had to be paid not to the devil, but to God. And therefore Christ is said to have paid the price of our redemption—His own precious blood—not to the devil, but to God. _______________________
FIFTH ARTICLE [III, Q. 48, Art. 5]
Whether It Is Proper to Christ to Be the Redeemer?
Objection 1: It would seem that it is not proper to Christ to be the
Redeemer, because it is written (Ps. 30:6): "Thou hast redeemed me, O
Lord, the God of Truth." But to be the Lord God of Truth belongs to
the entire Trinity. Therefore it is not proper to Christ.
Obj. 2: Further, he is said to redeem who pays the price of redemption. But God the Father gave His Son in redemption for our sins, as is written (Ps. 110:9): "The Lord hath sent redemption to His people," upon which the gloss adds, "that is, Christ, who gives redemption to captives." Therefore not only Christ, but the Father also, redeemed us.
Obj. 3: Further, not only Christ's Passion, but also that of other saints conduced to our salvation, according to Col. 1:24: "I now rejoice in my sufferings for you, and fill up those things that are wanting of the sufferings of Christ, in my flesh for His body, which is the Church." Therefore the title of Redeemer belongs not only to Christ, but also to the other saints.
On the contrary, It is written (Gal. 3:13): "Christ redeemed us from the curse of the Law, being made a curse for us." But only Christ was made a curse for us. Therefore only Christ ought to be called our Redeemer.