.... And how does S'char V'onesh work (in Beis Din)?
We also believe that if Hashem lets Beis Din do something to a person, it's because He wants it to happen. No? There are many possible "explanations", and there are also times when a person can't be punished by Beis Din because of lack of witnesses etc.
We don't have to worry about these things; there's Someone else in charge...