The Bible says, and we know, that there are other planets out there. By faith we understand that the worlds were framed by the word of God. (Heb 11:3) What exactly do those worlds look like? Does anyone live on them? Will we ever communicate with them if they do? Jesus said, And other sheep I have which are not of this fold. (Jhn 10:16) Does He mean they’re Gentiles, or on another planet?
These are all fun and interesting questions. It’s probably better not to have them answered because there’s so much entertainment value to the guessing. But the fact is, it doesn’t actually matter, and no theology should be based on what we think exists in the universe. God has given us all that we need to know for salvation and living in His kingdom.
God is certainly big enough to manage our world and hundreds like this one, but whether or not that’s the case is not a matter of faith. We are responsible for the truth we’ve been given, not what we guess. ET may have a home somewhere out there, but it doesn’t change who God is to us.