Can seers see demons? This question comes up a lot.Yes!  It is likely that seers see demons, and they see them a lot.A teenager in my ministry sees spirits all the time and she is certain many are demons.  My daughter says she sees spirits all the time and often they are demons.  I do not believe, however, that they can see all the demons in a particular location. I don't know why they can see some and not others.

What are demons? 

There are many kinds of spirit entities, from extremely powerful territorial spirits to the spirits that Jesus described who roam the earth looking for a person to attack or a place to dwell in. The Hebrew Bible does refer to the "gods" that the pagan nations surrounding Ancient Israel worshipped as "demons." For the most part, the word "demons" should be understood to refer to the spirits which are now earth-bound and roam the earth.I'll present a few theories about the origin of demons.[ref]Parts of this page are drawn heavily from Forbidden Gates: How Genetics, Robotics, Artificial Intelligence, Synthetic Biology, Nanotechnology, and Human Enhancement Herald the Dawn of the Techno-Dimensional Spiritual Warfare, chapter "Your Hidden Enemy", by Tom and Nita Horn (Defender Publishing, 2011).[/ref] 

1. Are Demons the spirits of dead wicked men? 

This is a popular assumption today. It assumes that the spirits of humans (ghosts) leave their body to travel to "the other side" to live in bliss, either in Heaven or becoming "one with everything."The belief is, for whatever reason, some don't make it.  Some of these ghosts get stuck along the way or get lost traveling to the other side, and are stuck roaming the earth, maybe haunting houses, reliving certain experiences, and so on.They try to communicate with Ghost Hunters, or just make a ruckus.Some are summoned by psychics with "messages" to their living relatives. Some are angry they are dead.  Some "don't know they're dead", according to The Sixth Sense. Others are "deceived," according to Poltergeist, while still others just get stuck.  Some are evil, and these evil ghosts are demons.I used to think that ghosts were bunk. But then I looked at what the Bible suggested.  This article explores ghosts and what they may be. I now conclude it's likely that some demonic activity originates from the spirits of dead humans.However, I also believe most demonic activities are not from ghosts, but from demons impersonating ghosts. Spirits that pose as ghosts have their own agendas.

2. Are demons otherworld beings (aliens, UFO's)?

Some believe that intelligent life is visiting earth not from other dimensions, as we argue on this site, but from other worlds, and these beings are demons.  Certainly aliens act like demons when they afflict, abduct, and torture people, while preaching a weird message of a coming messiah.However, it's more likely that demons are acting like aliens, rather than aliens acting like demons.While intelligent life may exist on other worlds throughout the universe, I find it unlikely they would be visiting earth merely to "demonize" some humans. However, given the obsession our culture has with alien invasions and abductions, "aliens from another dimension" (demonic entities) could extend significant influence over the planet by imitating aliens from other worlds.

3. Are Demons fallen angels? 

First of all, it should be noted, the phrase "fallen angels" does not appear in the Bible. Keep that in mind when thinking about these topics.The idea that demons are fallen angels is a popular teaching.  It's based on the belief that at some time in the past, Lucifer rose up in a great rebellion and declared war on God in heaven. He persuaded a third of all angels to stand with him in insurrection. At this point, God expelled Lucifer and his angelic army out of heaven, and they came to earth to become demons.Lucifer is the Latin word for "morning star".  In some English translations of the Bible, it's placed in Isaiah 14:12, as the translation of the Hebrew phrase "hel'el ben shahar." This phrase translated in English is "Shining One, son of the dawn." In the ancient world, the first light of the morning was known to be Venus, the morning star, so some scribe, when translating the Hebrew into Latin, naturally interpreted "Shining One, son of the dawn" as Venus, or "the morning star": Lucifer in Latin.Isaiah 14 is a passage that taunts a human tyrant, and compares him to a divine being who overstepped his bounds, wanting to be like the Most High. Some see this as a description of Satan, although that connection isn't as obvious as it sounds.[ref]See http://drmsh.com/the-naked-bible/morning-star/.[/ref] They interpret that passage and a possible parallel passage in Ezekiel 28 to mean in the distant past, Lucifer was an annointed "cherub" (throne guardian) who rebelled and was cast out of heaven.Centuries after Isaiah wrote this taunt, when Jesus sent his 70 (or 72, depending on the translation) disciples to the nations to preach and cast out demons, he stated he saw Satan cast down from heaven. It's unclear if he meant at that time , which contextually makes sense, or in some distant past (linking it to Isaiah 14), which also makes sense based on other assumptions.  Similarly, the timing of the passage in Revelation that refers to a third of the angels falling from heaven with Satan is unclear to some.The Book of Job does in fact declare God does not trust his angels, suggesting they can "fall" or rebel at any time.[ref]Job 4:18[/ref]  However, much errant theology can be derived from verses taken out of context of the overarching narrative in Job, which is about how Job's efforts to earn God's favor really had nothing to do with God showing him favor, and why Job blamed God for the pain in his life really had nothing to do with God.Regardless, the angels - be they territorial spirits entities or lesser angelic beings - who rebelled against the Most High God can exhibit demonic behavior, but to me it's doubtful that they are specifically demons.

4. Are demons the spirits of the dead offspring of angels/gods and women? 

The written records of every culture of the ancient world held that spirit beings descended from heaven, materialized into bodies of flesh, had sex with human women, who gave birth to a new breed of humans. The ancient Hebrews called these spirit beings "Watchers" and the "sons of God." Most other cultures simply called them "gods."The new breed of humans had demonic spirits with human bodies, but possessed mutations that made them abnormally strong, intelligent, and large.   The Ancient Greeks called them Titans. The Ancient Hebrews called them "nephilim" (translated as "giants") and stated some were up to 10 feet tall. Some of these hybrids founded nations (i.e., Romulus and Remus were the sons of Mars and a temple prostitute, who founded Rome, according to Roman myths).Ancient Hebrew records and other ancient myths declare these beings overran the earth in the distant past, consuming all natural resources, and began consuming humans to the brink of extinction, until the human race was saved by a global flood, killing all or most of these hybrids, although they do appear after the global flood in limited locations.  The spirits of the Nephilim killed in the flood, the first century Christians held, roam the earth as demons, looking for new bodies to inhabit or to afflict.Incidentally, these giants and their descendants (the Nephilim and Rephaim in the Hebrew Bible) were the great nemesis of the Ancient Hebrews in their scriptures from their Exodus of Egypt until the Conquest of their Promised Land.

5. Are Demons mental hallucinations?

No doubt, some people see things that are not related to the spiritual world, but rather to psychological trauma.Yet, the spirit world is real, is inhabited by intelligent beings who interacts with our world in real ways.