One of the strongest proofs for Christianity is the absence of extraterrestrial intelligent beings:
As the article stipulates, Christianity teaches man as God’s special creation, a creation for whom God sacrificed His only Son. These other beings would either need to be perfect, having never fallen; or they would need to have been redeemed in the same manner that man was redeemed. If such creatures knew nothing of Christ, Christianity would make little sense.
How could God judge these creatures without revealing Himself to them?
But we have been searching for extraterrestrial intelligence for some time, to no avail. Given that we are neither at the edge of our galaxy where life would have spontaneously developed earliest; nor at the center of our galaxy, where life might be expected to develop later; a naturalistic model for life would assume forms both more and less advanced than our own. The advanced forms would certainly generate electromagnetic signatures which would be detectable and demonstrably synthetic.
The lack of such EM evidence provides a strong argument for the premise that man is alone in the galaxy (and by extension, the universe). This fits perfectly with the Christian worldview, but is inexplicable to the modern, approved secular and naturalistic worldview.
In order for extraterestrial life to have fallen, they would have to have disobeyed a command from God, such as don’t eat from the tree.
To be of God’s children, they would have to have been willing to sacrafice something/someone of high value, like Abraham was about to do. And God would have had to accept them as His children.
To be of God’s adopted children, they would have to be baptised and accept Jesus. And have the Faith that this is good enough for God.
Extraterestrial aliens, if they exist, would have the same status as dogs. Or monkeys. As the intelligence of any creature pales in comparison to God, the intelligence of ET is NOT a condition for entry into heaven.
I would not make the lack of certain piece of scientific evidence a condition of proof. Future technology may be able to overcome this barrier. The Catholic church made that mistake with Galileo.