well the batshit crazy but actually plausible angle of this is that spiritual beings exist due to our electromagnetic "exhaust" that our bodies create. these are angels/demons/boogie men/fairies/gnomes etc. these are non-physical beings that are sometimes invisible to our naked eye. they exist on a different part of the uv spectrum.  these entities have evolved over time to feed off of our electromagnetic exhaust, our "faith" which is created as blood is pumped through our brains and makes electromagnetic circuits and electromagnetic radiation waves. so anyway, demons made a deal with these aliens because being demons they feed off of the negative emotions of humans and their suffering- their plan, working as a team, is to cause both the greatest suffering to the greatest number of people (to feed and sustain the demons/evil entities for a long time), while also eventually killing these people, leading to humanity being fractured and so nearly destroyed that we become wild men again and forget everything we knew. we will hopefully, one day in the future be able to grow again to the point of discovering the technology we have today, but this will take millions of years. and we may not survive that long.
Tree Hugger