(4) The only ground for [eschatological] hope lies in the steadfast love and faithfulness of God, which is testified to by the resurrection of Jesus Christ (John Polkinghorne, Science and the Trinity: The Christian Encounter with Reality. New Haven: Yale University Press, p. 166).
There is no doubt that much reflection in the area of eschatology is highly speculative. While such speculation is coherent and credible, it remains tentative. And, yet, Christian eschatological hope "has a firm foundation, for it is anchored in the resurrection of Christ" (p. 166).
Polkinghorne believes (and I agree) that the belief in the bodily resurrection of Jesus within history is a credible affirmation.* From this belief Polkinghorne sketches three basic theological affirmations.
First, the resurrection of Jesus affirms the faithfulness of God. Good Friday appeared to call that faithfulness into question, thus the "deathly silence of Holy Saturday" (p. 167). But on Easter Sunday, God did indeed provide the last word. In the resurrection new life was given as a divine gift. Death and futility would not have the last word.
Second, the empty tomb is critically important. Polkinghorne writes, "This is not an altogether popular thing to assert today, since modern belief often tends to find difficulty with any concept of the bodily resurrection of Jesus. Again we see at work a spiritualising tendency that at first sight may seem to make belief easier, but which, in the end, proves to be less than adequate for full credibility" (p. 166). Polkinghorne has rightly made the case that full humanity requires embodiment. Such embodiment is intrinsic to what it means to be human. In the risen Jesus we encounter resurrection, which is not a mere resuscitation, that is, a Jesus brought back to life in the same mortal body. Rather the Gospels attest to a resurrected Jesus-- "not the same as the body of his earthly life, [but] derived from that earthly body as its glorified transmutation through the death-defeating power of God" (p. 168).
Jesus resurrected and glorified body is not only an affirmation of the eternal destiny of humanity, but for the entire created order. The same matter that constituted Jesus' body is the same matter that makes up the entire universe. If such matter is transformed for eternity in Jesus, then it is logical and coherent to believe that the entire universe is to be redeemed. "The empty tomb is a sign not only of Christ's resurrection, but also of the cosmic significance of that great event" (p. 168).
Third, "what happened to Jesus within history is the foretaste and guarantee of what awaits the rest of humanity beyond the end of history" (p. 168). The resurrection of Jesus was the commencement of the second and final phase of creation. The fulfillment of God's creation and "the consummation of the divine purpose and the satisfaction of human longing" (pp. 168-169) has already begun.
Polkinghorne ends his discussion: "A credible theology depends upon it and, in turn, a Trinitarian and incarnational theology can assure us of its credibility" (p. 169).
*Polkinghorne makes a case for Jesus' resurrection in his book, The Faith of a Physicist. (Philadelphia: Augsburg/Fortress, 1996), chapter 6.