She’s Gone

In a world where mythical beings exist, they are extremely rare and feared. They are feared because of their overpowered nature and the inability to keep their godly powers in check. The entire world has made it their goal to wipe out these beings because of their lack of control. The only problem is that they look just like normal people.

How are they supposed to find out who is what?
Why do they not try to help the people?