All this has been gone over in many other nodes:
Problem of Evil,
Omniscience and free will are contradictory,
God can't be all good and all powerful at the same time,
Beyond Belief: Why God Cannot Exist
Free will defense,
God has no free will,
to name a few.

There's always something more to add on to the debate. None of the write-ups here are decisive. Many philosophers have built careers writing about the argument from evil, both for and against, and will continue to do so until God appears to us, each and every one, and proves beyond a doubt that He really does exist, thus making our attempts at disproving Him fruitless.

My favorite spanner to throw into the works is "Okay, so maybe we need evil. How to you figure that we need so much of it, and why do some people have to experience (through no fault of their own) more evil than others?"

So there.


Because I can never stop arguing, here's a little more:

Without day, there is only night. Without a wrong way there is only the right way. Without evil, there is only good.

Is this true? Beats me. But it sounds at least as reasonable as m_turner's statement. Beware of metaphor.