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.
Objection 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.
Objection 3. Further, since Christ's Resurrection is the cause why bodies rise again, the bodies of all men shall rise again, according to 1 Corinthians 15:51: "We shall all indeed rise again." But the souls of all will not rise again, because according to Matthew 25:46: "some shall go into everlasting punishment." Therefore Christ's Resurrection is not the cause of the resurrection of souls.
Objection 4. Further, the resurrection of souls comes of the forgiveness of sins. But this was effected by Christ's Passion, according to Apocalypse 1:5: "He washed us from our sins in His own blood." Consequently, Christ's Passion even more than His Resurrection is the cause of the resurrection of souls.
On the contrary, The Apostle says (Romans 4:25): "He rose again for our justification," which is nothing else than the resurrection of souls: and on Psalm 29:6: "In the evening weeping shall have place," the gloss says, "Christ's Resurrection is the cause of ours, both of the soul at present, and of the body in the future."
I answer that, As stated above, Christ's Resurrection works in virtue of the Godhead; now this virtue extends not only to the resurrection of bodies, but also to that of souls: for it comes of God that the soul lives by grace, and that the body lives by the soul. Consequently, Christ's Resurrection has instrumentally an effective power not only with regard to the resurrection of bodies, but also with respect to the resurrection of souls. In like fashion it is an exemplar cause with regard to the resurrection of souls, because even in our souls we must be conformed with the rising Christ: as the Apostle says (Romans 6:4-11) "Christ is risen from the dead by the glory of the Father, so we also may walk in newness of life": and as He, "rising again from the dead, dieth now no more, so let us reckon that we (Vulgate: 'you')" are dead to sin, that we may "live together with Him."
Reply to Objection 1. Augustine says that the resurrection of souls is wrought by God's Substance, as to participation, because souls become good and just by sharing in the Divine goodness, but not by sharing in anything created. Accordingly, after saying that souls rise by the Divine Substance, he adds: the soul is beatified by a participation with God, and not by a participation with a holy soul. But our bodies are made glorious by sharing in the glory of Christ's body.
Reply to Objection 2. The efficacy of Christ's Resurrection reaches souls not from any special virtue of His risen body, but from the virtue of the Godhead personally united with it.
Reply to Objection 3. The resurrection of souls pertains to merit, which is the effect of justification; but the resurrection of bodies is ordained for punishment or reward, which are the effects of Him who judges. Now it belongs to Christ, not to justify all men, but to judge them: and therefore He raises up all as to their bodies, but not as to their souls.
Reply to Objection 4. Two things concur in the justification of souls, namely, forgiveness of sin and newness of life through grace. Consequently, as to efficacy, which comes of the Divine power, the Passion as well as the Resurrection of Christ is the cause of justification as to both the above. But as to exemplarity, properly speaking Christ's Passion and death are the cause of the forgiveness of guilt, by which forgiveness we die unto sin: whereas Christ's Resurrection is the cause of newness of life, which comes through grace or justice: consequently, the Apostle says (Romans 4:25) that "He was delivered up," i.e. to death, "for our sins," i.e. to take them away, "and rose again for our justification." But Christ's Passion was also a meritorious cause, as stated above (1, ad 4; 48, 1).
Source: Summa Theologica (New Advent)