Much of Thomas’s discussion of Jesus’ resurrection has an “Abelardian” flavor. The resurrection is less an integral part of the “accomplishment” of redemption and more a support for the life of the believer. Of the five reasons given for the necessity of the resurrection, only one is about the achievement of salvation. The resurrection commends divine justice, confirms faith, raises hope, and sets in order the lives of the faithful (ST III, 53, 1). Finally, fifthly, he says that the resurrection completes (complementum) the work of salvation; His death delivers from evil, the resurrection “advances us to good things.”
When he turns to a discussion of the fittingness of a third-day resurrection, he stays in this “subjective” vein: If Christ had not been raised so soon, we’d doubt His Godhead; if He had been raised instantly, we’d doubt His humanity and the reality of His death; therefore “Christ’s resurrection was necessary for the instruction of our faith.” Besides, the resurrection on the third day adds to the mysticism of the number 3.
But then this:
The third-day resurrection “signified that a third epoch (tertium tempus) began with the resurrection. To the eras ante legem and sub lege, the resurrection adds a tempus sub gratia. Further, the resurrection initiates (incipit) a third status for the saints. Once saints were sub figuris legis, then under the truth of faith (veritate fidei), but there will be another state of eternal glory, which Christ’s resurrection inaugurates (quam Christus resurgendo inchoavit).
This is quite remarkable: The objective effect of the resurrection is to begin a new stage of human history, a new epoch or tempus. Thomas also hints at an already-not yet structure to redemption by saying that the state of future resurrection is already inaugurated in Christ’s own resurrection. Alongside his “Abelardian” pieties, Thomas gives a very “kingdom-oriented” understanding of the resurrection.