lol @ all the super-sophisticated skeptics who relentlessly tear apart reports of miracles, and scream to the four winds that God is a lie for stupid people, then immediately get all serious about alien beings from another planet visiting the goddamn Earth in super-secret starships that sometimes advertize their existence by flashing pointless lights. Think they're just trying to bring a little Christmas cheer to this Halloween Town?
Now, if you're talking extraterrestrials, medieval philosophers wrote whole libraries about them because every religion, including Christianity, has always believed in extraterrestrials as a matter of faith. The Bible is full of them. The medievals call them "the intelligences." The Bible calls them "messengers," or "the watchers." The philosophy of angels got quite sophisticated a thousand years ago, right down to the fact that while they are immaterial intelligences, far more intelligent than human beings, and they sometimes take bodily form. Now here's the creepy part: they cannot take living forms, for only the human soul is the form of a living body. Rather, angels take on the form of dead bodies. They cannot see, they cannot feel. They merely animate a dead body to fulfill certain purposes that cannot be done by speaking in our heads, which is their primary form of interaction with humans. Most importantly, not all angels are good, and they have their own history that predates the existence of humanity. Sounds like jolly good sci-fi; it's actually all lifted from St. Thomas Aquinas, among many others. You chaps ought to read some of his Summa Theologica to get some story ideas. Draw a comic or something. Make a game.