Hello
I've always wondered if aliens existed. Many Christians say yes while many say no. Something I just read stated many Christians believe they do as why would God create such a huge universe? The answer to that was that to our minds it's huge but to God's, probably not. However, despite this, many Christians still believe aliens could exist.
Given the sheer vastness of the universe it seems unlikely that one tiny little planet tucked in the corner of a galaxy among billions of other galaxies is the only place where life of any kind exists.
It's possible, it just seems mind-boggling that it would be the case.
As to whether or not life actually does exist outside of earth, there's just no way to say. We literally can't say anything one way or another. But it seems reasonable to think that the possibility is good, again, given the sheer size of the universe.
Would God have created aliens and not told us? Would He have visited each creation separately and created a Bible separate for each species?
There were people living on continents right here on earth that the Church didn't know even existed until Europeans accidentally bumped into the Americas five hundred years ago. The Bible isn't a compendium of facts about the universe, it is a collection of texts which the Church believes and confesses shares the story of God's redemption in Christ.
As for the second part of your question, that's completely unknowable. My thoughts tend toward analogy: Jesus was a Jew born in a tiny little frontier province of the Roman Empire. And yet the Word becoming flesh was for all people, every nation, tribe, and tongue. For Christians living five hundred years ago the idea of people living across the ocean in the Americas was about as radical an idea for them as the idea of intelligent creatures living on distant worlds is for us today. To that end, as we believe that God's purpose in Christ is for the redemption and renewal of all creation, not just human beings, it's not altogether impossible to think that ultimately the only real difference between discovering people on another continent on earth and discovering people on other planets is merely one of scope. However, that's just one possible way of looking at the subject among others.
Given that we literally know nothing one way or the other on this topic, there is endless speculation to be had without anything resembling a substantive answer.
-CryptoLutheran