Reasons to Believe

How Would the Discovery of Extraterrestrial Life Affect Biblical Creation Models?

With the recent discovery of so many “habitable” planets, I have been bombarded with questions on my Twitter page about how the discovery of extraterrestrial life would impact our biblical creation model. Eighteen years ago I, along with Christian astronomers Sam Conner and Guillermo Gonzalez, wrote a Facts & Faith article where we answered the question of how (and to what degree) the discovery of different kinds of extraterrestrial life would impact a variety of biblical creation models.1 A lot has happened, both scientifically and theologically, during the past 18 years. Clearly, it is time for an update.

Remains of Life Will Be Found on Most Solar System Bodies
I have been on record since the 1980s in predicting that the remains of life will be found on the moon, Mars, and several other solar system bodies. What makes this discovery inevitable is that millions of tons of Earth’s soil have been exported throughout the solar system owing to large meteorites striking Earth. A large enough meteorite impacting Earth will generate enough energy to cause rocks, soil, dust, and water on Earth to be ejected into interplanetary space. Over time, much of that material lands on the moon, Mars, Venus, the moons of Jupiter, and other solar system bodies.

The amount of Earth’s life exported to other solar system bodies is far from trivial. Embedded in the rocks, soil, dust, and water ejected from Earth, there will be microbes and small multicellular life-forms. On average, a ton of Earth soil contains one hundred quadrillion microbes. On average, about 200 kilograms (440 pounds) of material from Earth has been deposited on every square kilometer (0.38 square miles) of the lunar surface.2 For Mars, the figure is about 2 kilograms per square kilometer.

Is there a chance that viable Earth life will be found on some other solar system body? The probability is remote, but it is not impossible. There are microbes on Earth that can withstand intense radiation, long periods of desiccation, and highly saline solutions. If by some incredibly lucky chance they traverse the distance from Earth to Mars, for example, in just hundreds of years rather than the typical millions of years, and if by some incredibly lucky chance they land on Mars in a briny pond near the equator on an exceptionally warm day, they might survive and live.

Is it possible for the remains of Earth life to be transported to some planetary system beyond the solar system? The answer is yes. However, by the time such remains reach an exoplanetary system, those remains would be so degraded as to be unrecognizable as having originated from a living organism.

Biblical Constraints and Options for Extraterrestrial Life
The Bible teaches that God created extraterrestrial life—the angels. Angels, however, unlike us, are not confined to the universe and are not constrained by the physical laws that govern the universe.

The Bible is largely silent on whether or not God created physical extraterrestrial life that is subject to the laws of physics. Therefore, Christians, unlike nontheists, are free to believe whatever they want about extraterrestrial life, with one caveat. Hebrews 9:26, 28 says of Jesus Christ, the Creator of everything that was created:

He has appeared once for all at the culmination of the ages to do away with sin by the sacrifice of himself. . . . So Christ was sacrificed once to take away the sins of many. (NIV)

This passage asserts that there is just one sacrifice for the sins of all and that this one sacrifice took away the sins of many people. Thus, there is the strong implication that only one physical, intelligent, spiritual species exists in the universe that is in need of redemption from sin. To argue otherwise requires expanding the definition of people to include more than human beings, and the doctrinal aberration (many theologians would say heresy) that no incarnation on another planet is necessary to save physical spiritual beings on that planet from their sin.

There is no passage of Scripture, however, that explicitly excludes the possibility of God creating physical life on other planets that is not in need of spiritual redemption. So, for example, God could have designed a planet far, far away on which he created bacteria, or a planet on which he also created mosses, ferns, and trees, or a planet on which he also created animals, including those that are as active and intelligent as dolphins and crows. The Bible even permits creatures on another planet that are as intelligent and spiritual as we humans, providing that they have never sinned and, thus, would not be in any need of redemption.

The question of extraterrestrial life does raise an interesting theological debate. Is it more in keeping with God’s revealed character for him to create life on many other planets, or for him to limit his creation of physical life to only our planet?

It doesn’t take much exploration of Earth to recognize that God has packed our planet with as much life as possible, which is as diverse as possible and as beautiful and elegant as possible. As the psalmist declares,3

How many are your works, Lord! In wisdom you made them all; the earth is full of your creatures.

It seems that God really enjoys the act of creating. Given how much he relishes creating, why would he limit his creation of life to just one planet? Thus, one could deduce from this component of God’s character that extraterrestrial life would be abundant and ubiquitous.

On the other hand, much biblical content supports the doctrine that God is conservative in the performing of his miracles. That is, God limits his miracles to those that are necessary to achieve his purpose. Therefore, we would not expect God to perform a creation miracle that does not fit his purpose for creating.

God’s primary purpose in creating is to eliminate the possibility of evil and suffering while at the same time enhancing the free will capability of the spiritual beings that he has created who choose to be redeemed by him from their evil. This purpose raises a question: How many planets on which physical spiritual beings exist does God need to fulfill his purpose in creating? Just one seems like the most likely answer theologically. Thus, based on God not performing gratuitous miracles, we would expect to find exoplanetary systems to be barren of life.

Astrophysical Constraints on Extraterrestrial Life
A common rebuttal to the view that God has limited his creation of life to just our planet is the vast size of the universe and the enormous number of planets that exist in the universe. There at least two responses to this rebuttal.

The first is that there can be no planet Earth unless the universe is precisely the mass and size that it is. A universe even a tiny bit less massive than ours would never possess elements heavier than helium. A universe even a tiny bit more massive would not possess elements lighter than iron. Likewise, unless the mass, expansion rate, and size of the universe is exquisitely fine-tuned, the universe will never produce galaxies, stars, and planets. In other words, given the laws of physics that God has chosen to govern the universe, there is no chance of a single planet like Earth existing on which physical intelligent life is possible unless the universe is exactly the mass, size, and age that ours is.4

Second, everywhere astronomers look beyond our planet, they see conditions that are very hostile to advanced physical life. Our galaxy is the only one we observe that possesses all the characteristics needed for advanced physical life.5 Our planetary system is the only one out of the thousands we observe that possesses the array of planets, asteroids, and comets that advanced physical life needs.6 In fact, we now know that every planet in our solar system must be designed the way it is for advanced life to be possible on Earth. We also now know that Earth is the only planet out of the 3,500+ we have discovered that resides in all nine known habitable zones.7 Furthermore, the sun is the only star out of the millions we have measured in sufficient detail that possesses the characteristics required for advanced physical life.

The astrophysical evidence, therefore, leans strongly toward the doctrinal position that in this universe God has limited his creation of life to just our planet. Does this mean that we humans are alone? No. When a human being receives God’s offer of redemption from their sin, at that moment the Holy Spirit takes up permanent residence within that human. Thus, anyone who is a new creature in Christ is not alone, not now and not for the rest of eternity. Also, Hebrews 13:2 says that many of us have entertained angels without knowing it. Even if we have not had physical contact with angels, the Bible says that the angels are intently observing us humans to learn about God’s grace.

Possible Apologetic Opportunities If Extraterrestrial Life Exists
It is already well established that the origin of life on Earth could not have occurred through any conceivable naturalistic pathway.8 The possible discovery of extraterrestrial life would provide another example of a divine miraculous intervention. Given that the only explanation for the origin of life is a divine miraculous intervention, the discovery of life in another planetary system would establish not just one origin-of-life miracle but two. The more exoplanetary systems in which life is established to exist, the more origin-of-life miracles would be established. Thus, the possible discovery of extraterrestrial life would yield even more evidence for the supernatural handiwork of God.

It is debatable, however, whether the discovery of extraterrestrial life would cause a large number of nontheists to repent of their atheism and become Christians. As Jesus said in a parable directed at the religious leaders of his time, “If they do not listen to Moses and the Prophets, they will not be convinced even if someone rises from the dead.”9 Similarly, if nontheists refuse to recognize the origin of life on Earth as a supernatural event, they are unlikely to do so for life on another planet.

God has already given us overwhelming evidence from the record of nature of his existence, his attributes, and his purpose for creating the universe and us. And every day that evidence increases. We need to communicate that evidence to as many people as possible and pray that they will humble themselves before their Creator and receive him as their Creator, Savior, and Lord.


  1. Sam Conner, Guillermo Gonzalez, and Hugh Ross, “A Spectrum of Views on ETI,” Facts & Faith 12, no. 2 (second quarter 1998): 10–11,
  2. John C. Armstrong, Llyd E. Wells, and Guillermo Gonzalez, “Rummaging through Earth’s Attic for Remains of Ancient Life,” Icarus 160 (November 2002): 183–96, doi:10.1006/icar.2002.6957.
  3. Psalm 104:24 (NIV).
  4. Hugh Ross, Why the Universe Is the Way It Is (Grand Rapids: Baker, 2008), 27–41.
  5. Hugh Ross, “The Milky Way: An Exceptional Galaxy,” Today’s New Reason to Believe (blog), Reasons to Believe, July 30, 2007,; Hugh Ross, “Galactic Spurs and Feathers,” Today’s New Reason to Believe (blog), Reasons to Believe, November 1, 2003,; Hugh Ross, “Milky Way Galaxy’s Midlife Crisis,” Today’s New Reason to Believe (blog), Reasons to Believe, October 3, 2011,; Hugh Ross, “No Ordinary Galaxy,” Today’s New Reason to Believe (blog), Reasons to Believe, November 15, 2010,
  6. Hugh Ross, Improbable Planet: How Earth Became Humanity’s Home (Grand Rapids: Baker, 2016), 43–93.
  7. Hugh Ross, “‘Electric Wind’ Becomes 9th Habitable Zone,” Today’s New Reason to Believe (blog), Reasons to Believe, July 4, 2016,
  8. For example, building block molecules—like ribose, arginine, and lysine—essential for assembling even the simplest conceivable organism are completely missing outside of living organisms, the decay products of living systems, or sophisticated biochemistry laboratories. Nor is there any naturalistic pathway for building a pool of amino acids that are all left-handed in their configuration or ribose sugars that are all right-handed in their configuration. See Hugh Ross, “Rare Amino Acid Challenge to the Origin of Life,” Today’s New Reason to Believe (blog), Reasons to Believe, April 11, 2011,; Fazale Rana and Hugh Ross, Origins of Life: Biblical and Evolutionary Models Face Off (Covina, CA: RTB Press, 2014), 125–36.
  9. Luke 16:31 (NIV).

Subjects: Meteors, Origin of Life, Theology, Life on Other Planets, Panspermia, SETI