The gap theory helped many Christians in the nineteenth century bridge the chasm between traditional interpretations of Genesis 1-2 and the emerging fossil record. Few people still read the Bible that way, but it was once championed by Thomas Chalmers (1780-1847), the Scottish churchman and eloquent gospel preacher. On the other side of the Atlantic, Timothy Dwight (1752-1817) drew his congregants into the beautiful power of orthodoxy. President of Yale College from 1795 until his death in 1817, and husband of one of Jonathan Edwards’ daughters, Dwight wooed his hearers with evangelical sermons against the Deists of his day.

Both preachers were icons of ardent, Bible-centered, evangelical piety, and both of them saw extraterrestrial life as one more proof of the glory of God. Filling the cosmos with all manner of alien life would be a small thing for an omnipotent God. As Chalmers put it in his Astronomical Discourses, God seeded the universe with planets, “mansions of life and of intelligence.”Thomas Chalmers, Astronomical Discourses, cited in Michael J. Crowe, The Extraterrestrial Life Debate 1750-1900: The Idea of a Plurality of Worlds from Kant to Lowell (Cambridge: Cambridge University Press, 1986), 185. Chalmers was responding to the plurality of worlds critique leveled against evangelical religion.

Astrotheology as an Old Debate

The discipline of astrobiology investigates the origin, nature, and future of life in the universe, drawing on astronomy, physics, biology, chemistry, ecology, and several other disciplines. “Astrotheology” (or exotheology) is the field that works out the theological implications of astrobiology. This academic field may not be on the radar of most laypeople, but they still have plenty of opinions about extraterrestrial life, some of those opinions shaped by Hollywood thrillers and science fiction page-turners—on the latter, Cixin Liu’s Three Body Problem trilogy is a breathtaking example.The first of the three volumes is Cixin Liu, The Three-Body Problem, trans. Ken Liu (New York: Tor Books, 2014). The other volumes are: The Dark Forest (vol. 2) and Death’s End (vol. 3).

But as Dwight and Chalmers remind us, these are not entirely modern questions. The possibility of extraterrestrial life was widely debated in the nineteenth century, and believers had different opinions on these issues. Astrotheological musings were common even earlier: Plato, Aristotle, and Democritus all speculated on whether there was life on other planets, as did patristic and medieval thinkers (who were usually naysayers).For a history of this long debate, see Crowe, The Extraterrestrial Life Debate.

Alien Theological Puzzles

Believers today have different intuitions about alien life. Some worry that if we ever discover extraterrestrial life, the theological implications would be massive, perhaps catastrophic. The discovery would potentially destabilize the Christian faith and fundamentally change our understanding of the biblical story.For a similar perspective, see W. Gary Compton, “Are UFOs Biblical?The Trinity Review 305 (April 2012): 1-4. Other Christians meanwhile shrug their shoulders; no doubt it would be an astonishing discovery, but the impact on the faith would be negligible. Perhaps it would even increase our love and appreciation for the greatness of our triune God.This rosy attitude is expressed by the experts interviewed on the PBS episode, “Extraterrestrial Intelligent Life.”

Imagine if scientists found creatures of comparable or greater intelligence than us. If such aliens do exist, would they be sinners or sinless? And if they are sinners, did Christ make atonement for their sins? Or, wherever they may be in this vast universe, was Christ’s life, death, and resurrection sufficient for them since the God-man redeemer is the cosmic Christ? Maybe the Son of God became incarnate on every single planet with intelligent life? Multiple incarnations—let a thousand Christmases be celebrated across the galaxies! These are mind blowing theological questions, and we are just scratching the surface. Admittedly, these questions are also very speculative. Whatever we think about the plausibility of alien life—and I count myself among the non-believers—these are still intriguing questions.

NASA continues to search for extraterrestrial life. Over 3,700 exoplanets so far have been discovered, a figure that will likely explode in coming decades (“exoplanets” are planets that orbit a sun beyond our solar system).E.g., Pat Brennan, “What in the World is an ‘Exoplanet’? Our technological capacities keep improving, and experts say it is only a matter of time before we discover alien life in the universe. But what are theologians saying about extraterrestrial life? What are Christians to make of this growing field of research?

In our first installment of “Fresh Voices,” a series introducing our readers to new areas of science-theology research, we have gathered a group of scholars to comment on the significance of astrotheology: Andreas Losch, Thomas O’Meara, Ted Peters, and Jeff Zweerink. If Tertullian came back from the dead, he might well ask them: What has Mars to do with Earth? That’s a good question; throw in one or two aliens and now we’re really talking. Join us for a parley on astrotheology and what it might mean for Christian witness.