Chariots of fire?
Some say that Elijah was taken up in a "space ship" based on the description in 2 Kings 2:11 and 2 Kings 6:17.
Are these really "space craft" or are they just a description of a fiery whirlwind, and the only frame of reference in those days was chariots or horses that they could use to describe it?
Whatever it was, it was not "aliens". It was a visual representation of God taking Elijah to another place. It was interdimentional travel. Just as angels and evil spirits are really a sort of interdimentional being.
The realm of God and His angels is something like another dimension outside of this physical realm that we live in. What we know as "the sea" in Daniel 7 is the sea of creation, which is the physical realm that we live in. This is really a basic understanding we need in order to understand who God is. God is not part of the universe. If you looked everywhere, in every corner of the universe, you would not find God. He exists completely outside of it. He created the universe and all physical things, but he's not a part of it. He became part of it by being born into it as a man in Jesus Christ, but the Spirit which is God does not exist in the same realm that we do. For the sake of argument, we can call it another "dimension".
But there are no "aliens" in the Bible, nor are there any aliens (a sapient species from another planet) that have ever been proven to exist in this universe.
Over and over in the Old Testament we see that "devils" are the false gods that people sacrificed to, and worshiped, instead of God. (Lev 17:7, Deut 32:17, 2 Chr 11:15, Ps 106:37, etc.)
These evil spirits have been luring people away from God for thousands of years! They pretend to be gods as well as other things!
The 5th section of Dan 2's prophecy of the kings, the iron mingled with clay, is a two-part section that "doesn't mix", and is partly strong and partly broken. Some people say that verse 43 is talking about aliens, but again, it's just the "devils" and evil spirits.
Dan 2:43 And whereas thou sawest iron mixed with miry clay, they shall mingle themselves with the seed of men: but they shall not cleave one to another, even as iron is not mixed with clay.
The Djinn or Jinn of Islam (genies) are evil spirits, or devils
Is this the "they" that mingle themselves with the seed of men?
The clay of Daniel 2 that doesn't mix with the iron is definitely Islam. This has been proven by history. See - The Iron and Clay of Daniel 2
Islam is a false religion manufactured by Satan and the evil spirits are massively "mingling" with Muslims. This is most likely what verse 43 is talking about.
Angels can appear as a man if they choose to:
Enoch and Jasher show us that they can appear as pretty much anything; animals, bodies of water, men or women, etc.
2 Peter and the book of Enoch gives us details about the punishment of these angels that sinned, which gives us clues about who these evil spirits are and where they came from.
2 Pet 2:4 For if God spared not the angels that sinned, but cast them down to hell (Tartaroo, the deepest abyss of Hades), and delivered them into chains of darkness, to be reserved unto judgment;
They are all locked away in the lowest part of Hades until judgment day. Those angels that sinned are not the devils or evil spirits that were spoken of in the Old Testament after the flood, and in the New Testament, and are currently in the world today.
It's the children of these fallen angels that are "evil spirits" who have been confined to the earth, that are spoken of and exist today.
Offspring of angels that sinned are confined to the earth as evil spirits (Enoch chapter 15)
Demons, devils, ghosts, etc., are these evil spirits... (ghosts are likely these pretending to be a ghost to create fear and confusion).
Legion and the other devils in Jesus' day are these evil spirits.
Revelation 9:1-12 describes a "locust" type creature which stings with its tail and has a poison like a scorpions poison (this is a horrible poison that produces intense pain, drooling, muscle twitching, etc., but does not kill adults). It has hair like women, faces like men, gold crown on it's head, shaped like horses, teeth of lions, breastplates of iron, and it's wings sound like many horses running to battle...
The below might seem a bit scary to some, but these are artist renditions of what this creature might look like. My point in showing them to you is that these might appear to be something alien, and I believe Satan has created this belief in aliens so he can cause people to believe they're aliens instead of listening to God and heeding His warning!
The creatures in the 5th trumpet will probably be touted as aliens by the mainstream media and the world, when it happens.
They will hurt people for 5 months, and their sting will be like the sting of a scorpion. Men will seek death but won't find it.
This is the first of three WOE's of Revelation. See - The 7 Trumpets
Luke 8:31 Legion asked not to be commanded to go into the "bottomless pit" (the deep), which is the same word used in the 5th trumpet!
Will the "locusts" be demons who manifest themselves into the creatures described in Revalation 9, when the bottomless pit is opened?
Satan has set the world up for it, so the world will think they're "aliens", or possibly some "evolved" creature. We know aliens are not Biblical, but devils are, and Satan has created this idea of aliens, along with "evolution", so he can distract and obscure the truth when the trumpet blows.
We know that there are evil spirits and fallen angels, but that Satan is not one that was imprisoned at the time of the flood, and that he will take a third of the angels of heaven with him when he's cast to the earth at the time of the Antichrist (Rev 12), so it's likely that some of the angels are working with Satan now, and these are also in the world deceiving and lying and creating doubt and confusion along with these spirits which are the offspring of the fallen angels, which is what Satan does best.
Dan 10:13 shows that there are evil spirits that attempt to thwart the angels doing God's work.
NO, there are no aliens... they are evil spirits pretending to be aliens! They are attempting to fool us and confuse us!
See more information on the book of Enoch here
See more information on the book of Revelation here