Thank you for raising this topic. It is my belief that Evil must be present for Good to be defined. Only by having 2 points can you measure time (now and then), space (here and there), or value (good and bad, or evil). If I am "here" (the first point), were is "here"? If "here" is 20 miles from you (the second point) now you can understand where "here" is. Without a second point "here" is simply where I AM. "There" is simply where YOU ARE.
So if we assume that there is a God with a distinct personality, and that God is directly interested in our greatest fulfillment, we HAVE to see that God created both Good and Evil at the same time. Good and Evil are only concepts measured in relation to each other. Before these concepts were created (the option of free-will) God was simply God, for being Good would assume some relation to Evil. For example, does anyone consider animals to be evil? We may say they are Good, but only in realtion to our values. Is a lion Evil for preying on a sick vulnerable antelope? No, the lion is only doing what is natural.
Here is an interesting question: Did Satan create God? By Satan exercising the right to choose what was not God, did Satan produce the actions and premise that cause Jews, Christians, and Moslems to worship the way they do? (I include these religious groups because their doctrinal root "God vs Devil" are the same.) By separating humans from God (through imperfection) did Satan dictate God's limitations with how the "Almighty" could interact with God's own creation? Did Satan create God as we know "God." Yes!
I bring up this point to show that any belief that God is only pure Good and did not create Evil is faulty. A JW would say that God "lovingly" provides free-will to angels and humans so that we are not robots. However anyone choosing Evil is destroyed (at least eventually). I would say that is not free-will, it's the most expensive-will we know - it costs your life! It would be more reasonable to state that Satan is in the employ of God, providing a testing opportunity for all angelic and human creation.
What we all know and agree is that we appreciate how Good God is only because of the Evil that afficts us. Is it not Evil that draws people to religion to get the answers they crave? Thank God for Satan. Indeed, without the Devil who would need God?
The Devil's Advocate