Evil against God

As I sit here amazed by the atrocities that took place a few days ago, the pure evil where no mercy was shown I wonder how one can even argue that there is evil in this world. And since evil is present, than good must also be, because just as the absence of good reveals evil, so does the longing for mercy, grace, peace,love, and dare I say justice, point toward a good God that will "make things right".