I see parallel's to Milton's "Paradise Lost".
Angels were not human and Satan[Lucifer] was cast out of Heaven to Pandamonium[ Hell on Earth] .
Satan[Lucifer], Uziel, Uriel and other former angels were jealous of God's love of humans over them.They created a war in heaven that Miton vividly imagines. [ But then human's create war as well].
Satan lives as a demon[alien] tempting man while he lives out his time on earth. Many fail, breaking God's commandments. A test, a decision with consequences, showing that man's free will can be deadly to other humans.
Just an observation. But Milton was clear that Satan and his Legion[ We are Legion] are not human and, basically, detest and envy humans.
This can be greatly extended. And God in Heaven can be construed as a friendly alien force or so all the great main religions teach that salvation is possible, although Judaism, stresses God's "covenant" is a contract that expires on death--although the Karbala has angelic script and describes the great war in heaven that erupted after God created man and woman.
I a, too, agree with others who have written, that there are clear paralllel's to "Donnie Darko". The police chief and father in law was the same actor that played Donnie's father in that movie.