Objection 1: It would seem that Christ ought not to have suffered on the cross. For the truth ought to conform to the figure. But in all the sacrifices of the Old Testament which prefigured Christ the beasts were slain with a sword and afterwards consumed by fire. Therefore it seems that Christ ought not to have suffered on a cross, but rather by the sword or by fire.
Obj. 2: Further, Damascene says (De Fide Orth. iii) that Christ ought not to assume "dishonoring afflictions." But death on a cross was most dishonoring and ignominious; hence it is written (Wis. 2:20): "Let us condemn Him to a most shameful death." Therefore it seems that Christ ought not to have undergone the death of the cross.
Obj. 3: Further, it was said of Christ (Matt. 21:9): "Blessed is He that cometh in the name of the Lord." But death upon the cross was a death of malediction, as we read Deut. 21:23: "He is accursed of God that hangeth on a tree." Therefore it does not seem fitting for Christ to be crucified.
On the contrary, It is written (Phil. 2:8): "He became obedient unto death, even the death of the cross."
I answer that, It was most fitting that Christ should suffer the death of the cross.
First of all, as an example of virtue. For Augustine thus writes (QQ. lxxxiii, qu. 25): "God's Wisdom became man to give us an example in righteousness of living. But it is part of righteous living not to stand in fear of things which ought not to be feared. Now there are some men who, although they do not fear death in itself, are yet troubled over the manner of their death. In order, then, that no kind of death should trouble an upright man, the cross of this Man had to be set before him, because, among all kinds of death, none was more execrable, more fear-inspiring, than this."
Secondly, because this kind of death was especially suitable in order to atone for the sin of our first parent, which was the plucking of the apple from the forbidden tree against God's command. And so, to atone for that sin, it was fitting that Christ should suffer by being fastened to a tree, as if restoring what Adam had purloined; according to Ps. 68:5: "Then did I pay that which I took not away." Hence Augustine says in a sermon on the Passion [*Cf. Serm. ci De Tempore]: "Adam despised the command, plucking the apple from the tree: but all that Adam lost, Christ found upon the cross."
The third reason is because, as Chrysostom says in a sermon on the Passion (De Cruce et Latrone i, ii): "He suffered upon a high rood and not under a roof, in order that the nature of the air might be purified: and the earth felt a like benefit, for it was cleansed by the flowing of the blood from His side." And on John 3:14: "The Son of man must be lifted up," Theophylact says: "When you hear that He was lifted up, understand His hanging on high, that He might sanctify the air who had sanctified the earth by walking upon it."
The fourth reason is, because, by dying on it, He prepares for us an ascent into heaven, as Chrysostom [*Athanasius, vide A, III, ad 2] says. Hence it is that He says (John 12:32): "If I be lifted up from the earth, I will draw all things to Myself."
The fifth reason is because it is befitting the universal salvation of the entire world. Hence Gregory of Nyssa observes (In Christ. Resurr., Orat. i) that "the shape of the cross extending out into four extremes from their central point of contact denotes the power and the providence diffused everywhere of Him who hung upon it." Chrysostom [*Athanasius, vide A. III, ad 2] also says that upon the cross "He dies with outstretched hands in order to draw with one hand the people of old, and with the other those who spring from the Gentiles."