And this is reasonable. Because the principle of human life-giving is the Word of God, of whom it is said (Ps. 35:10): "With Thee is the fountain of life": hence He Himself says (John 5:21): "As the Father raiseth up the dead, and giveth life; so the Son also giveth life to whom He will." Now the divinely established natural order is that every cause operates first upon what is nearest to it, and through it upon others which are more remote; just as fire first heats the nearest air, and through it it heats bodies that are further off: and God Himself first enlightens those substances which are closer to Him, and through them others that are more remote, as Dionysius says (Coel. Hier. xiii). Consequently, the Word of God first bestows immortal life upon that body which is naturally united with Himself, and through it works the resurrection in all other bodies.
Reply Obj. 1: As was stated above, Christ's Resurrection is the cause of ours through the power of the united Word, who operates according to His will. And consequently, it is not necessary for the effect to follow at once, but according as the Word of God disposes, namely, that first of all we be conformed to the suffering and dying Christ in this suffering and mortal life; and afterwards may come to share in the likeness of His Resurrection.
Reply Obj. 2: God's justice is the first cause of our resurrection, whereas Christ's Resurrection is the secondary, and as it were the instrumental cause. But although the power of the principal cause is not restricted to one instrument determinately, nevertheless since it works through this instrument, such instrument causes the effect. So, then, the Divine justice in itself is not tied down to Christ's Resurrection as a means of bringing about our resurrection: because God could deliver us in some other way than through Christ's Passion and Resurrection, as already stated (Q. 46, A. 2). But having once decreed to deliver us in this way, it is evident that Christ's Resurrection is the cause of ours.
Reply Obj. 3: Properly speaking, Christ's Resurrection is not the meritorious cause, but the efficient and exemplar cause of our resurrection. It is the efficient cause, inasmuch as Christ's humanity, according to which He rose again, is as it were the instrument of His Godhead, and works by Its power, as stated above (Q. 13, AA. 2, 3). And therefore, just as all other things which Christ did and endured in His humanity are profitable to our salvation through the power of the Godhead, as already stated (Q. 48, A. 6), so also is Christ's Resurrection the efficient cause of ours, through the Divine power whose office it is to quicken the dead; and this power by its presence is in touch with all places and times; and such virtual contact suffices for its efficiency. And since, as was stated above (ad 2), the primary cause of human resurrection is the Divine justice, from which Christ has "the power of passing judgment, because He is the Son of Man" (John 5:27); the efficient power of His Resurrection extends to the good and wicked alike, who are subject to His judgment.
But just as the Resurrection of Christ's body, through its personal union with the Word, is first in point of time, so also is it first in dignity and perfection; as the gloss says on 1 Cor. 15:20, 23. But whatever is most perfect is always the exemplar, which the less perfect copies according to its mode; consequently Christ's Resurrection is the exemplar of ours. And this is necessary, not on the part of Him who rose again, who needs no exemplar, but on the part of them who are raised up, who must be likened to that Resurrection, according to Phil. 3:21: "He will reform the body of our lowness, made like to the body of His glory." Now although the efficiency of Christ's Resurrection extends to the resurrection of the good and wicked alike, still its exemplarity extends properly only to the just, who are made conformable with His Sonship, according to Rom. 8:29.
Reply Obj. 4: Considered on the part of their efficiency, which is dependent on the Divine power, both Christ's death and His Resurrection are the cause both of the destruction of death and of the renewal of life: but considered as exemplar causes, Christ's death—by which He withdrew from mortal life—is the cause of the destruction of our death; while His Resurrection, whereby He inaugurated immortal life, is the cause of the repairing of our life. But Christ's Passion is furthermore a meritorious cause, as stated above (Q. 48, A. 1). _______________________
SECOND ARTICLE [III, Q. 56, Art. 2]
Whether Christ's Resurrection Is the Cause of the Resurrection of
Souls?
Objection 1: It would seem that Christ's Resurrection is not the cause of the resurrection of souls, because Augustine says (Tract. xxiii super Joan.) that "bodies rise by His human dispensation, but souls rise by the Substance of God." But Christ's Resurrection does not belong to God's Substance, but to the dispensation of His humanity. Therefore, although Christ's Resurrection is the cause of bodies rising, nevertheless it does not seem to be the cause of the resurrection of souls.
Obj. 2: Further, a body does not act upon a spirit. But the
Resurrection belongs to His body, which death laid low. Therefore His
Resurrection is not the cause of the resurrection of souls.