The search for extraterrestrial life is picking up steam. What does it mean for Christian theology?
Over the last few decades, more than 3500 planets have been discovered around other stars. Identifying and studying such planets, known as exoplanets, has become an important sub-field of astronomy. Key questions focus on whether such planets can or do harbor life: do these planets lie within their stars’ habitable zones, where temperatures would allow for liquid water to exist? Do their atmospheres contain complex carbon molecules, which could be evidence of biological processes, or at the very least of chemical processes associated with life? Life thriving in exotic, inhospitable places here on earth—such as hot thermal vents deep in the ocean, with no sunlight—implies that life can exist in more extreme conditions than we once thought. Tiny animals known as tardigrades can even survive in the vacuum of space. There is evidence of liquid water elsewhere in our own solar system, such as Jupiter’s moon Europa, which raises the tantalizing possibility that extraterrestrial life might be in our own back yard. The possibility that we will discover conclusive evidence of life away from earth seems to grow more likely each day.
If and when that happens, it will be one of the most important discoveries in the history of humankind. It will forever alter humanity’s self-understanding and our sense of purpose in the cosmos. We will suddenly know for sure what we have long suspected, and perhaps dreaded: we are not alone in the universe, and earth is not special in the cosmic scheme of things. If we find evidence that such life is intelligent, we will know that humans are not unique even in that respect.
What would such a discovery mean for Christian theology, which holds that humans are created in the image of God, and that God’s Son became incarnate as a human being and died to save humans from sin and death?
One of the first things people point to when considering a Christian response to the discovery of extraterrestrial life (especially intelligent life) is the Christian understanding of humans as something special. In the creation narrative in Genesis 1:1-2:4, God creates human beings in the divine image. God blesses humankind and gives them dominion over all other creatures, commanding them to “be fruitful and multiply, fill the earth and subdue it.” Psalm 8 likewise marvels that humans are “a little lower than God” despite their apparent lack of majesty in comparison with the moon and stars (Psalm 8:5). In the second creation narrative, Genesis 2:5-3:24, the whole world is forever altered by the actions of the first two humans, who choose to eat from the tree of the knowledge of good and evil. The biblical narrative of the redemption of all creation hinges on the redemption of humankind. In the Gospel of John, Jesus is the divine Word made flesh, the light and life of all creation who becomes a human beings (John 1). Jesus’ death on the cross and resurrection from the dead saves humankind from the power of sin and death. In the Bible and throughout Christian theology, humankind is a special creation of God: we bear the divine image, we have a tremendous responsibility toward the rest of creation, and we are the focus of redemption.
The discovery extraterrestrial life, especially intelligent life, would suddenly raise all sorts of questions about humankind’s special status. If there are other intelligent beings out there, did God need to become incarnate in their species and die on their planet as well? If so, what does that say about God? If not, why are we so important? Many philosophers, scientists, and even theologians see the claim of human uniqueness within creation as a shortcoming of Christianity. We once thought our home was the center of the universe, after all. But now we know that we are one of eight planets orbiting a typical star in an ordinary galaxy in an impossibly vast space. Christianity has managed to hold onto human uniqueness so by pointing to our intelligence, among other things. If we were to find intelligent extraterrestrial life, the reasoning goes, the discovery would complete the revolution that Copernicus started. Because human uniqueness is so central to Christianity, it seems like Christianity would have to reconsider a number of significant doctrines and theological affirmations.
But I’m not so sure. Christian theology holds that humans are special, but we also believe God often works through ordinary people who are unremarkable except for the fact that God chooses them. God intervened on behalf of Israel, delivering them from Egypt and making them God’s chosen people. God did this not because they were more numerous, or mightier, or more virtuous than other nations, and not even because they had suffered more. God did this because God made a covenant with Abraham, the choice of whom is equally perplexing. God chose Jacob instead of Esau while they were still in the womb, before either one had a chance to accomplish or deserve anything. God chose to be born of the virgin Mary, who was also nothing special save for the fact that God chose her. Jesus was not a citizen of the mighty Roman empire, but one of its subject peoples. His hometown was so unremarkable that Nathanael would scoff “can anything good come out of Nazareth?” (John 1:46). Throughout the Bible, God chooses particular people who are not the mightiest or most intelligent or most righteous, but special only because God chose them. That is the scandal of election, and it too is an important part of the Christian faith.
So even if we are not entirely comfortable with it, Christianity is already at least used to this idea that something can be of deep significance without being unique, and that God’s decision about whom to work through is mysterious.
These questions, like so many others about our faith, won’t be easy to answer and will require the deep, thoughtful reflection of faithful men and women. But the biblical idea of election, of God having a chosen people, might well shape our reflection on the place of humankind in the larger universe if and when we discover that human life is not, in the end, very special.