1) I answer that, He properly atones for an offense who offers something which the offended one loves equally, or even more than he detested the offense. But by suffering out of love and obedience, Christ gave more to God than was required to compensate for the offense of the whole human race. First of all, because of the exceeding charity from which He suffered; secondly, on account of the dignity of His life which He laid down in atonement, for it was the life of one who was God and man; thirdly, on account of the extent of the Passion, and the greatness of the grief endured, as stated above (46, 6). And therefore Christ’s Passion was not only a sufficient but a superabundant atonement for the sins of the human race; according to 1 John 2:2: “He is the propitiation for our sins: and not for ours only, but also for those of the whole world.” Thomas Aquinas, Summa Theologica, Part 3, Q 48.2.
2) The very least one of sufferings was sufficient of itself to redeem the human race from all sins; but as to fittingness, it sufficed that He should endure all classes of sufferings, as stated above. Thomas Aquinas, Summa Theologica, Part 3, Q 46.5.
3) 1 John 2:22 He is the propitiation for our sins, for some efficaciously, but for all sufficiently, because the price of his blood is sufficient for the salvation of all: but it has no efficacy except for the elect because of an impediment. Thomas Aquina, “Commentaria 1 Tim. 2:1-6a,” in Omnes D. Pauli Apostoli Epistolas Commentaria. (Liege: H. Dessain, 1858), 3:68. [Personal translation, Marty Foord.]
David Paraeus citing Aquinas:
4) Thomas writes: “The merit of Christ, as to its sufficiency, extends equally to all, but not as to its efficacy, which happens partly on account of free will, and partly on account of the election of God, through which the effects of the merits of Christ are mercifully bestowed upon some, and withheld from others according to the just judgment of God.” [Source: Commentary on the Heidelberg Catechism, 224.]
5) Of the redemption purchased by the passion of Christ we may speak in a double sense & signification, either respecting the sufficiency thereof; & so his passion redeemed all because as concerning himself he delivered all. [Source: David Paraeus]
John Davenant quoting the same:
6) Aquinas also observes (Quest. disp. de grat. Christi. art. 7, reap. ad 4,) The merit of Christ as to its sufficiency equally regards all men, but not as to its efficacy; which arises partly from free-will, partly from the election of God, through which the effect of the merits of Christ is mercifully conferred upon some, but is by his just judgment withdrawn from others. [Source: John Davenant, Dissertation on the Death of Christ, 543.]
Kimedoncius citing Aquinas:
7) Hereupon Thomas in 1 Tim. 2. says: “Christ is the propitiation for our sins: for some effectually, for but for all sufficiently, because of the price of his blood is sufficient to save all, but it has not effect but in the elect, because of an impediment.” And more clearly upon 5. Apoc. he says: “We speak of the Lord’s passion two manner of ways. Either according to the sufficiency, and so his passion redeemed all: for it is sufficient to redeem and save all, although there were even more worlds, as Anselm says, lib. 2. Cur Deus &c., homo. cap. 14. Or according to efficiency and so not all are redeemed by his passion, because all cleave not to the redeemer, and therefore not all have the efficacy of redemption.” The same man says: “The merit of Christ as touching the sufficiency is alike to all, but not as touching the efficiency: which happens partly through freewill, partly through God’s election, by which the effect of Christ’s merit is bestowed upon some mercy, but it is withdrawn fro others by the just judgment of God [Idem summa de veritate materia 26. quest. 7.].
Against the Gentiles, lib. 4. cap. 55, he alleges this cause of the foresaid distinction between sufficiency and efficiency. “The death of Christ” (says he), “is as a certain universal cause of salvation, as the sin of the first man was as it were the universal cause of damnation. But the universal cause must be applied to everyone particularly, that he may receive the effect of the universal cause. The effect of the sin of our first parents comes to everyone by our fleshly birth. But the effect of death of Christ comes to everyone by spiritual regeneration, whereby man is after a sort joined unto Christ, and incorporated unto him.” Other testimonies of this author we have before alleged. [Source: Iacob Kimedoncius, Of The Redemption of Mankind (London: Imprinted by Felix Kingston for Hvmfrey Lownes, 1598), 235. ] [Some reformatting; some spelling modernized; marginal comments cited inline.]