The recent discovery of water on Mars raises one of the usual questions many moderns ask of Christians, does the existence or possibility of life on planets other than Earth somehow constitute an argument that Christianity is untrue? I will acknowledge from the outset that my arguments on this point have been enriched by C S Lewis’ essay “Religion and Rocketry; ”it’s a good essay, and well worth reading.
The Vastness of Space and Christianity
It is often asserted that the vastness of space is a sufficient argument that Christianity is untrue. This argument, however is incoherent; on what grounds precisely does the vastness of the universe undermine Christian thought? How does the largeness of space outside of our terrestrial ball prove that Jesus was not resurrected from the dead? The point of the vastness of space is immaterial, one way or the other, to the truth value of Christianity. Medieval theologians, thinkers and poets were well aware that space was vast, and saw no contradiction with Christianity, why should we?
Sometimes this objection is rephrased, it is noted that mankind is not the center of the universe, and therefore the idea of God’s grace for mankind makes no sense. But, once again, on what grounds does mankind have to be the center of the universe for Christianity to be true or to make sense? In point of fact, the Bible does not present man as the center of the universe, either spiritually or physically; the place of man as the spiritual center of the universe is to displace the Creator who rightfully occupies that place. Man is not the object of grace because of mankind’s importance, but because of God’s goodness.
More to the point, it is a false assertion that medieval thinkers put the earth at the center of the universe because it was assumed the stars and planets revolved around us. In point of fact, medieval thinkers inherited such views from Aristotle and other Greek thinkers. The Bible references the earth and the planets, but it makes no assertions about the earth’s place in the universe, what references do exist are largely poetic, in the same vein as our own tendency to refer to the sun’s rising, rather than discussing the movement of the Earth. Arguments to the contrary for the most part are simply chronological snobbery. Nor were Aristotle’s arguments based on man’s centrality, they were simply the best explanation to the observations available to the unaided eye and senses.
Nor would the existence of extraterrestrial life per say be a challenge to the faith; additional information about said life would be necessary to make any coherent argument, and modern man is in no place to answer those questions. For example, one must find not just life, but intelligent, sentient (however this might be defined) life. Animals or plants have no value to the objection against Christianity, and in fact, are an argument against evolutionary theory. If plants, microbes or animals are found on mars, then one must explain the long odds of life on two planets in the same solar system. Say what you will about life, from what we know of biology it is extraordinarily complex and relatively fragile (at least after the fall).
Even if sentient life is found, what we would learn from such an enterprise is pure speculation. Perhaps we would find a race of men who were unfallen, as Lewis hypothesizes in the first and second novels of his space trilogy, Out of the Silent Planet and Perelandra. Perhaps we would find a race of aliens that is fallen, and has some other means of redemption, or has grounds for redemption in the crucifixion. This approach, if it sounds far fetched is ultimately no more nor less imaginative than assuming we might find Spock, Chewbacca or ET on other planets. Indeed, this itself is the problem, our entire understanding of the theoretical possibility of intelligent life on other planets is shaped by Gene Roddenberry, H G Wells and other writers of Science Fiction. While their creativity provides interesting stories, the key word in “Science Fiction” is still “Fiction.” This arguing that Christianity is untrue on these grounds, then, are raising baseless speculation, nothing more.
 This essay can be found in Fern-seeds and Elephants. Some of these arguments also appear in his larger work, Miracles: A Preliminary Study and The Discarded Image.