Many science-fiction stories have explored the idea of traveling through time and changing the past. For example, 1980’s “The Final Countdown” imagined a modern-day U.S. aircraft carrier being transported back to 1941 and facing the choice of either thwarting the Japanese attack on Pearl Harbor or allowing history to play out unchanged. In the early 1990’s, the TV time traveler Dr. Sam Beckett would “Quantum Leap” into other people’s lives, “striving to put right what once went wrong.” Just last fall, the internet hotly-debated the morality of going back in time to kill Adolf Hitler when he was still too young to have chosen or have committed any crimes.
Is it possible to go back in history and change the past? There’s good reason to think that it is logically impossible. Here is why: Imagine traveling back in time and, by some tragic accident, killing your grandparent as a child. This would mean that one of your parents would have never been born… so you would have never been born… which raises the question: who killed your grandparent? Or imagine a time traveler’s intended history-changing mission succeeding, such as stopping JFK’s assassination. If so, then there is no cause for the time traveler to have ever been sent back from the future at all. This sort of logical contradiction is called a paradox.
Most serious time travel stories avoid this paradox problem using the premise that the past can be visited but never truly altered. Time travelers simply fulfill the role they have always played in those past events. Any and all attempts to avert some disaster in history will either prove useless or actually contribute to bringing about the calamity.
Time travel is merely fantasy, but the prophesies of God, which have correctly foretold future events, are very real. Consider, for instance, these passages from the 22nd Psalm written by King David under the inspiration of the Holy Spirit some 1,000 years before the coming of Christ:
“My God, my God, why have you abandoned me? … All who see me mock me… Like water my life drains away; all my bones are disjointed. My heart has become like wax, it melts away within me. As dry as a potsherd is my throat; my tongue cleaves to my palate… They have pierced my hands and my feet. I can count all my bones. They stare at me and gloat; they divide my garments among them; for my clothing they cast lots. … I will live for the Lord…”
This psalm is clearly fulfilled in Christ’s sufferings on the cross; the onlookers’ gloating mockery, the gambling over his garments, his dehydration and laboring heart, wounds cutting to his bones. What other form of torture is there that pierces the hands and feet? Jesus spoke this psalm’s opening words even while sharing the psalm’s closing hope in a life restored. These events were accurately described a millennium before they occurred.
God prophesying future events raises questions about human freewill. If Jesus’ crucifixion could be long foretold then what responsibility could Judas, Caiaphas, or Pontius Pilate possibly bear for their roles in the Passion? The answer is that Eternal God, from his vantage point outside of time, can behold all of history, including the free choices that each of us make. C.S. Lewis reconciles God’s knowledge and our freedom in these passages from his book “Mere Christianity”:
“…God is outside and above the Time-line. In that case, what we call ‘tomorrow’ is visible to Him in just the same way as what we call ‘today’. All the days are ‘Now’ for Him. He does not remember you doing things yesterday; He simply sees you doing them, because, though you have lost yesterday, He has not. He does not ‘foresee’ you doing things tomorrow; He simply sees you doing them: because, though tomorrow is not yet there for you, it is for Him. You never supposed that your actions at this moment were any less free because God knows what you are doing. Well, He knows your tomorrow’s actions in just the same way— because He is already in tomorrow and can simply watch you. In a sense, He does not know your action till you have done it: but then the moment at which you have done it is already ‘Now’ for Him.”
God’s knowledge of our free choices does not make our choices any less free. As St. Augustine once noted, “Just as you do not compel past events to happen by your memory of them, so God does not compel events of the future to take place by his knowledge of them.” God’s divine knowledge does not strip us of human freewill, but it does permit him to communicate perfect prophesies to his people concerning events further along our timeline. Such prophesies concern not only the Messiah’s life, but our times and future as well.
Jesus Christ has already victoriously prevailed. His Second Coming in glory is foretold and assured, and his people’s final victory over sin and death is prophesized and certain. This is the connection between time travel stories and the prophesies of God: like the futility of time travelers attempting to avert some historic disaster, any and all attempts to prevent the ultimate triumph of Christ will either prove useless or actually contribute to bringing about the coming of his Kingdom. The enemies of Jesus schemed to destroy him and his movement, but their very plotting led to the fulfillment of his mission and the birth of the Church. This knowledge is a cause for Christian endurance and joy, even amidst our times of struggle. We know that we are free to serve a faithful role in helping bring about the great, holy, happy ending of history.