Are UFO's demons? I would say no because it simply means unidentified flying object. But if the question was do I believe that the alien obsessed culture is demonic in origin, I would respond with a resounding "Yes!"
Those who insist there is life on other planets use a tired old argument that if there are so many stars in the galaxy and we can expect a certain number of them to have planets, then it's almost certain that a few of these planets have the right conditions for life. This postulation is not proof, but it's good enough for those who want to believe in E.T. Conveniently enough, this logic fits nicely with the theory of evolution, that life comes about by spawning and evolving from primordial ooze, not as a sovereign act of a Creator.
I think that the earth is unique in all the universe and separate as "God created the heavens and the earth" (Gen 1:1). The "heavens" and then the "earth". The heavens are flung out to the inscrutable expanses to bear testimony to this little planet that our God is great. They serve no other purpose but to give glory to God. Jesus, who is undisputedly the very God that created all this is incarnated and crucified on this tiny planet, the most significant event in the history of the universe. Angels and demons are all engaged in fierce battle over us. When one understands these spiritual truths about our significance in the Universe, one can only condlude that we are the epicenter of all events of consequence in the Universe.
Now back to space aliens. Are they not alot like what we read described in Scripture, the "powers of the air?" History is teeming with aparitions in the air. Dragons appeared in Europe and the Orient, two cultures that had no interaction for centuries, yet they both saw dragons. Is the dragon not described in Revelation 12? "Ascended masters" they are called, these "spirit guides" that the saavy Christian understands are demons. Hollywood portrays the assumption that we are accountable to them for our actions instead of the Almighty. "You pollute your planet and devise ever imaginative means of destroying yourselves." Assumed also is that these beings, not the Almighty, can bring final judgement to man. To those of a Christian world-view, we see the Usurper trying yet again to take the place of God. Nothing can be more demonic.
In Christ's most Sacred Heart