Why is murder bad?  If you don't believe in God or are not a Christian, why does murder matter?  Clearly it is wrong, but why?  Then again, for some cultures, it's not wrong at all and in fact some places in the United States don't seem as indivduals to have a problem with it at all.  Isn't evolution the strong killing the weak?  We accept it in nature?  Why not in humans if in fact humans did evolve from animals?