The discovery of an extrasolar planet always seems to be followed with a position on whether it is habitable or not. This is especially seen when it is claimed that the planet is terrestrial and within its star's habitable zone, also called the "Goldilocks zone" in reference to it being not too hot or too cold, but "just right" for liquid water. Then sensational speculation is published in the media that it may harbor extraterrestrial life. The presence of water alone though would not allow life to exist. There are a number of factors relating to habitability, a planet's size being but one of them.
Regardless of that fascinating issue though, a more pertinent concern is regarding the theological and especially the soteriological ramifications of extraterrestrial life. From the outset though it has to be made clear that discovering non-intelligent life is one thing, but finding intelligent human-like life would be quite another, regardless of one's perspective.
The difference is in the power to choose. Thus, finding bacteria, insects, animals or trees on another planet is fine as they cannot make decisions of right and wrong. Finding intelligent extraterrestrials though is quite another matter, since they can indeed make decisions of right and wrong. Additionally, such ones would have been created by the Universal Sovereign Creator, Jehovah, just as human life was created on earth as Adam and Eve.
Human life fell into sin by rebelling against Jehovah's Universal Sovereignty. At this point it is noteworthy that no faithful intelligent extraterrestrials were subpoenaed as witnesses against Adam and Eve. As one journal explained it:
[W]hen Adam and Eve sinned, they were, in effect, questioning God's right to rule over a world of intelligent physical beings. If another planet existed at that time, a world full of intelligent physical beings who were living harmoniously and loyally under God's rule, would they not have been called in as witnesses to testify that God’s rule does indeed work? This conclusion seems inescapable, since he has already used even imperfect humans as witnesses in his behalf on that very issue.—Isaiah 43:10.Thus at least when Adam and Eve sinned, there were no faithful extraterrestrials. It would also seem reasonable that Adam and Eve were the only sinners in the universe, as their sin came as the result of the first apostate angel called Satan. He first struck on earth and was successful at establishing apostasy there. Also surely the Creator would not populate multiple worlds simultaneously, but would do so one at a time in case there was a problem with one or two, or more of them. That would be a disaster of astronomical magnitude, for then a ransom sacrifice would have to be made for all of them one at a time.
Another point that harmonizes with this conclusion is what is stated at Job 38:4, 7. There we are told that the angels rejoiced greatly over the creation of the earth. If the earth was just one of many such planets with intelligent physical life, then we would not expect such applause. This angelic rejoicing over earth's creation is consistent with its uniqueness.
Thus the most logical, coherent, and scriptural position to take is that Adam and Eve were the only sinners in the universe and that there was no faithful extraterrestrial life. After a problem arose on earth, any planned peopling of planets was postponed. Therefore we are the only intelligent physical creatures in the universe. A discovery to the contrary would present a theological and soteriological dilemma for the reasons presented above.
What's the purpose of all those extrasolar terrestrial planets within habitable zones if they are not inhabited?
The same purpose of the solar terrestrial planets Venus and Mars that lay outside the habitable zone. They provide interesting comparisons to the uniqueness of Earth. Why assume that their purpose must be more than that? Keep in mind that there are a number of factors that need to be taken into account before creating intelligent life on a planet. All of these factors must be present.
What about Isaiah 45:18 that says that God made the earth to be inhabited and not empty or made for nothing. Doesn't this apply to other planets? (Actual question asked of me)
That scripture is stated of earth, and to apply it to other planets would be a misapplication. Just because another planet is devoid of life does not mean it was made for nothing—as if life is the only standard to measure the worth of a planet from. The bottom line is Isaiah 45:18 is stated about earth and is not a planetary principle.
Is not the Bible Earth-centric though?
It may be Earth-centric but the Universal Sovereign Creator, Jehovah is not. Thus we can be sure that (1) there were no faithful extraterrestrials at the time of Earth's apostasy and (2) there were no other apostate worlds at the time either.
Since the universe is so large it must be teaming with life?
We could apply the same question to an Olympic-size chlorinated swimming pool. Since it's so large it must be teaming with fish.
 Awake! 1990 April, 8 pp. 10-11 "Extraterrestrials—Finding the Answer." See also Awake! 1990 November, 8 p. 11 "UFO's—Can They Be Identified?" under "Is There an Occult Influence?" to explore the occult connection.
Related blog entry:
Science Increasingly Makes the Case for God
- The Privileged Planet http://www.theprivilegedplanet.com
- Exoplanets: Is the Earth Rare? http://www.evolutionnews.org/continuing_seri/exoplanets/
- In Search of Circumstellar Habitable Zones http://www.evolutionnews.org/2014/11/in_search_of_ci091461.html
- Reasons To Believe:
- Searching for Earth 2.0 http://www.reasons.org/articles/searching-for-earth-2-0
- Water Does Not Equal Habitability http://www.reasons.org/articles/water-does-not-equal-habitability
- Humanity is cosmically special. Here’s how we know.