It is not entirely paranoid to look at your fellow human beings as potential enemies--I believe that one of the quotes of General James Mattis of the US Marine Corps was "Be polite, be professional, but have a plan to kill everybody you meet." But it is not a good thing for the social fabric.
Here is the thing: your fellow human beings can have different kinds of hidden depths; they may look like everyone else but secretly be Chechen extremists who are alienated from the society they are living in. But, and this is the important thing, the hidden depths may be wonderfully magical ones as well and I am enough of an optimist to think that the number of sociopaths is relatively tiny compared to the number of people who have hidden talents and gifts.
Imagine if a group of utterly ordinary people walked into an art museum one day and with no preparation, just created out of nothingness a moment of sheer musical beauty. Here it is: