I see nobody takes this question seriously.
If you believe the New Testament, believe Jesus, have faith in scripture you MUST believe invisible creatures of malevolent intent can infest humans like lice.
At least a LEGION's worth.
How many in a Roman legion?
Wiki:
The size of a typical legion varied throughout the history of ancient Rome, with complements of 4,200 legionaries and 300 equites in the republican period of Rome, (the infantry were split into 30 maniples of 120 legionaries each), to 5,200 men plus auxiliaries in the imperial period (split into 10 cohorts, 9 of 480 men each, plus the first cohort holding 800 men).
So, why so many?
Isn't one enough?
The exaggerated number should alert us (who can still use our mind, that is) that our leg is being pulled!
HOW DO BELIEVERS defend the notion that thousands of invisible baddies take up residence inside a human being without WONDERING ( I know, I know--to "wonder" your brain has to be engaged in the thought you are thinking!) how this idea can be swallowed whole.
Any thinkers out there?
Or, just those with a bumper sticker brain: The bible said it, I believe it, that settles it!