The only certainty of life is that it all comes to an end. Death is the ultimate deadline around which everything moves. If nobody ever died, nothing would ever get done, because there would always be tomorrow to do it. Paradoxically death moves everything that happens in life into insignificance; death is still the end in any case.
“For there is no remembrance of the wise more than of the fool for ever; seeing that which now is in the days to come shall all be forgotten. And how dieth the wise man? as the fool.” (Eccl. 2:16)
Present moments are as puffs of smoke here, and never seen again. That which truly matters, matters in eternity. Nature itself, in the long run, leans toward death. The second law of thermodynamics tells us that order leads toward disorder. Creation itself is on its way toward inert energy.
Immortality entails participation in that which is immortal, and nothing in the physical universe is immortal. Immortality, if it is to be found at all, is to be found in that which transcends the physical. The world that is discernible by our five senses may point to it, but such is not to be found in it.
For the Christian, the answer is quite simple – it is in the resurrection of Jesus Christ. He lived again after having died. He lives eternally in a spiritual body not subject to death. If this is true, the case is closed. Death is not the end. “O death, where is thy sting? O grave, where is thy victory?” (1 Cor. 15:55). Conversely, for that same reason, the Christian’s hope for eternal life can rest on nothing else.
“And if Christ be not raised, your faith is vain; ye are yet in your sins. Then they also which are fallen asleep in Christ are perished. If in this life only we have hope in Christ, we are of all men most miserable.” (1 Cor. 15:17-19)
What is the testimony to us of our Lord’s resurrection today. All the witnesses to it have since passed; it is the testimony of the church, in the Scriptures, and in the rise of Christianity itself. It is the effect that one obscure carpenter turned itinerant preacher had on history. It won’t do simply say you do not believe the testimony. You would also have to find an alternative explanation as to how Christianity arose.
We, the body of Christ, do not hold hope in eternal life based on a future promise as did the Hebrews of old, or based on metaphysical speculation, as did the Greeks. We have confirmation in history.
“For the Jews require a sign, and the Greeks seek after wisdom: But we preach Christ crucified, unto the Jews a stumbling block, and unto the Greeks foolishness; But unto them which are called, both Jews and Greeks, Christ the power of God, and the wisdom of God. Because the foolishness of God is wiser than men; and the weakness of God is stronger than men. ” (1 Cor 1:22-25)