Scientific research for the existence of angels and demons?
People of all religious and agnostic beliefs have been fascinated as to whether the existence of angels and demons could be universally proven. Thus far in humankind history, the manifestation of angels and demons typically has been on an individual basis, leaving it to others whether they chose to believe the person who experienced these entities.
The belief in some kind of angelic-type spirit and a malevolent, evil spirit has been around humankind since the beginning, far, far before the advent of Judaism, Christianity, and Islam. The Jewish people take it on 100% that angelic and demonic beings exist because it is rooted in the definition, history, and religion of Yawheh, the One and Only Supreme Deity. As it has been said, God is not a man that He should deceive you.
Still, that begs the question of any scientific evidence for the existence of these entities. The scientific theory is that non-carbon-based sentient entities comprised of a peculiar, cohesive, yet unknown energy matrix are indigenous to Earth. You cannot see radio waves but you know they exist because your radio spouts music and talk, proving radio wave existence. You can't see x-rays but you know it exists otherwise the hospital x-ray scanner can't see within your body. Subsequently it must be assumed angelic and demonic entities exist within the non-visible portion of the light spectrum.
Beyond the religious beliefs of angels and demons originating from a single species before diverging, scientists cannot divine the nature of these entities along biological lines like carbon-based creatures on the planet.
Perhaps a small, electronics business owner in Southern California may have unwittingly recorded the visible existence of a possible demonic entity or entities. It's listed on YouTube under the, 'Exorcist Diaries'. A small business owner rented out a large, cavernous business building in southern Los Angeles for his electronics business. He had been alerted by the previous business renter about strange going-ons inside the building. Thus informed, the new renter planted an audio recording device. During playback, he heard, disturbing noises, shrieks, and inhuman sounds. Alarmed that pranksters, vandals, or thieves might be at work, he installed video. Watching the playback, he noticed objects moving at certain locations, always the same places while everywhere else nothing moved, ruling out an earthquake. Acting upon a personal scientific hunch, he installed an ultraviolet camera pointing at a desk where things would move during the night. The ultraviolet camera video playback proved interesting. Whenever something moved around the desk, a small, purplish, sparkling cloud appeared over the desk. He had no explanation for it. But maybe he just proved what everyone else suspected, these entities are made of energy. There is demonic guy with red skin, horns, cloven hooves, a forked tail, and carrying a trident. What you're seeing is what these 'things' look like as they are, an unknown energy mass that does not disperse but can move and manifest and appears to possess a sentient consciousness and purpose.
Religion tells us that many of these unseen entities are benign, even helpful. The others are malevolent, parasitic, and diabolical, motivated by hate and destructive intent.