Defing sin

no this isn't a how can we question, more like a why can't we...as in why can't we use the logic God used in Job to separate the righteous from sinners? It's still legitamite right?
My father says that you are a sinner if you change either internally (i.e. eat, sleep, urinate, deficate, etc...) or externally (i.e. again catch disease, and get hot or cold I guess). He then states if you are not a sinner you can grab a tornado and hurl it. Now how is that and Job valid arguments for today?

 

I guess that's the point....