Another question is, if actual Aliens with a conscience on par with ours along with an equal or higher intelligence did exist, would the Church be against a human marrying one?
Yes. There’s no way such a marriage could result in reproduction, according to the normal functioning of the organs in question (I don’t want to think about those organs). That’s the reason for the ban on gay marriage, but not, say, on marrying someone who had to have a hysterectomy/has a 0 sperm count/etc.
What happens if the first thing they say isn’t “Take me to your leader”, but rather, “We bring greeting from Pope Blar VIII, representative of Christ and the Holy Catholic Church on our planet. Oh… and you might wanna take a look at our scriptures too…” (I smell a book!! )
I’m actually writing a novel sort of along these lines. The thing is, the aliens have been told (by a mysterious woman cloaked all in blue…) to search the world (and universe) for their Godly Champion. They find him, of course, in the human race of the 24th Century, which, in the story, is not unlike the modern world, but in some ways worse (capitalism and socialism have compromised to create Belloc’s Servile State, for instance).
The aliens’ reaction is a bit like Augustine’s, upon first reading the Bible: what, these savages? Are you
serious?
There’s a lot more to it (hackers psionics AI swordfights gunfights languages warpdrive intrigue romance), but I’m thinking of calling the trilogy “Alien Messiah.” You know, those movies where Klaatu or ET comes down, and teach some pre-digested Hollywood gospel? Only this time, the alien Messiah is the Son of Man.
Incidentally, He’s their savior too, because, ontologically, all rational animals are one species, human. All nonrational animals are another, animal, and all nonmobile life is another, plant.