I have already discussed in previous articles the mathematical or cosmological argument for why extraterrestrial life probably exists and I have addressed at face value some philosophical concerns, but now I would like to undertake a theoretical examination of the implications aliens have for Christianity. 
I am sorry if you really do not care, but this is where religion gets interesting.  It is fine and dandy to simply say God only created mankind with souls, or even he only created life on Earth out of all places, but the moment we find real alien life or intelligences any argument for the uniqueness of man falls away. 
How would you like it if some Vogons or Twi’leks landed here and started to tell us they alone possess any sort of metaphysical soul? 
If and when we make contact, this is what we would be doing if we totally ruled out any spiritual or religious existence for aliens.
You could just say we are alone in the universe, meaning your religion does not need to change to fit a universal perspective, but I would be sure you have a backup plan in case some intergalactic monks come knocking on Earth’s door to inform us about our infidelity and their religion’s superiority to ours.
Basically, what I am trying to argue is this: if there is any sort of spiritual, metaphysical realm to this world, then any religion which makes use of it must take into consideration the possible existence of multiple races of intelligent, soul-possessing entities. 
The Bible does not explicitly say anything about anyone not directly descended from Adam, and Adam is generally accepted to have been on Earth, and in very recent history. 
In addition to the local claim of humanity’s fallenness is sometimes made the claim of the fallenness of the entire universe as a result of Adam’s sin. 
One view says the universe itself is not inherently fallen but it is only the humans who interact with it that are fallen, and another view says the entire universe has been cursed and altered drastically from its original form as a result of the fall. 
Now this theological question becomes central when aliens show up.  If those aliens are also souled beings like we are, then how could they have been cursed as a result of Adam’s sin; Hopefully Adam only represented humans. 
But at the same time, how could the entire universe not be fallen if even one of all the civilizations were fallen? Would not interaction between sinful and sinless races be just about impossible without something terrible happening? 
This is what C. S. Lewis addresses in his essay “Religion and Rocketry” in which he talks about how there most likely are other alien civilizations but they are not necessarily fallen. 
He suggests they could be completely unblemished, and so we should avoid contact lest we pervert them. 
In addition, C. S. Lewis’s book “Out of the Silent Planet” covers the potentiality for other races to have their own salvation structure, as the Martians have come to terms with naturally occurring death, seeing it as how the world works rather than some terrible painful experience to be avoided. 
Lewis’s sequel, “Perelandra,” examines closely the ability for a newfound race to not fall in the first place as well as the precarious danger of our meddling with such a race. 
I would suggest you read these works by Lewis as they are both entertaining and helpful to broaden ones perspective.
So, assuming every race gets its own chance to fall or to pass the test, if it is fallen, then does the atonement of Christ on the cross count for them too, is it even possible to not fall, and did he die for their race on their world as he did here, or is it our unique responsibility to tell the universe about Christ?
As I said before, the option which sounds most reasonable to me is this: the universe itself is not fallen; the only attribute of man which really changed after the fall of Adam was the initiation of the death of the soul as a consequence of rebellion, whereas death and hardship and pain had already existed, but the perfect moral standing and afterlife made it pleasant anyways. 
In this setting, it would make sense for each souled race to have its own Adam figure and if they fell then later to receive a functionally identical embodiment of God the Son to bring knowledge of his singular act of redemption of all souls. 
Now it could also be the case there was some sort of proto-Adam, before the universe as we know it either developed or was caused to exist and this proto-Adam represented all sentient beings and when he fell caused all to fall and did cause the entire universe to fall, initiating death, pain, etc. 
If this were the case, Jesus would probably come to every single civilization incarnate into its flesh to bring the news of his intercession for the punishment of the soul in his own spiritual death. 
I find it hard to believe we alone of all civilizations would be charged with spreading the good news to all worlds. 
It is fine to say evangelicals must minister to all nations, because at least everyone on Earth is the same species and shares common ancestry, but to be responsible for every other world is a bit of a stretch unless we soon discover how to travel the universe rapidly or are given divine assistance to do so.
MSU’s Reformed University Fellowship campus minister, Brian Sorgenfrei, in an email interview, said for him, the existence of aliens has no major impact on his worldview. 
Sorgenfrei remarked about the meat of Christianity, salvation. 
He said what matters the most is the image of God in mankind, as it is why God can become man and be our substitute.  From Sorgenfrei’s analysis, we can acknowledge our own ignorance of the universe and its intricacies and in the meantime remain content with God’s control of everything. 
Therefore, from a Christian perspective, other intelligences different than us could also be made in his image and consequently be candidates for Christ’s salvation in whichever way God sees fit.