If there is no moral and unchanging law... there is no evil...
At that point right/wrong is purely subjective and ever changing...
So if there is no God... there is no real evil... only transient and subjective wrongs...
If that were the case, then we would all be nothing more then animals. I believe that's the point of the whole argument.. I, for one, an NOT a monkey's uncle.. :)
I know that sounds awfully simplistic, but true none the less.