*Demons and Aliens
At first glance these two entities, whether real or not, appear to be very different. Demons populate New Testament times as Christ traveled from town to town casting them out of the afflicted. Demons make another big appearance in the art of the Middle Ages. A scene from an Hieronymus Bosch painting, "The Garden of Earthly Delights" shows demons torturing people in endless, creative ways. Demons are usually portrayed as hideous tormentors of mankind.
Aliens, as described by witnesses, are sleek and modern. They have shiny silver space suits and phenomenal flying craft made of unknown material that can do physically impossible maneuvers. They also, apparently, are capable of carrying out advanced scientific study and manipulation of the human body, the mind, even DNA.
In our culture there is a huge disconnect between scientists involved in SETI (Search for Extra-Terrestrial Intelligence) probing deep into space who have, by their own admission, discovered nothing alien and civilian eye-witness reports flooding into MUFON (Mutual UFO Network). Do we assume these hundreds of thousands of reports are all hoaxes or mis-identifications made by uneducated, gullible people? Are abductees making it up, in the process humiliating themselves? It turns out that there are credentialed scientists, even astronauts who have also filed these reports.
We can look beyond just these two entities to others that have populated our planet's history. Celtic mythology is rich with faeries, leprechauns and wee folk. The European tradition includes trolls, elves and gnomes. The Arabic countries have the Jinn. Our modern culture, ala Disney, has made child-friendly all these creatures- we have Tinker Bell, the Fairy Godmother, lucky leprechauns, I Dream of Jeannie (a Jinn) coming out of a bottle, and more recently, a very helpful traveling gnome with a sense of humor. They are all good-natured helpers of mankind.
The reality is that the original accounts of these creatures are much different. They are universally negative from the outright demonic behavior of the Jinn to the baby-kidnapping faeries of Scotland. The Irish often referred to the wee folk as the Good Folk out of fear of reprisal for any disrespect. Without exception they are devious and intrusive into people's affairs.
An excellent book by Jacque Vallee, "Passport to Magonia", details hundreds of these accounts from demons/fallen angels, to "fairy-tale" creatures to the modern aliens. The similarity among these creatures is startling when their behavior is compared. Two ideas in common with all of them is their hatred toward humans and their trans-dimensional qualities. It is as if their appearance and accoutrements morph slightly through time to fit the changing sensibilities of the population in question.
*What it means
If this theory is accurate then it explains why SETI cannot find any signs of alien life "out there" yet many report sightings and contact right here. It is because they are not from out there. Our modern "visitors" are simply the newest incarnation of a being that has lived among us in one form or another since time immemorial. They have outfitted themselves in an appearance of technological superiority in order to be believable in our current, rational, science-worshiping society. Nowadays we would laugh at a search for faeries but we spend billions looking for extra-terrestrials. The faeries of old stole babies and the demons tortured people- how is the reported alien abduction phenomena any different?