In my opinion, only human are good or evil, not God. Assign this human things to something that we dont know if exists or not, is an error and a way to avoid our own acts.
God created this world and man. And people themselves make this world good or evil. It all depends on who is treating different things and situations. And there are more good in this world.
God created the devil as a good angel. The devil turned against God and created evil. If evil was stronger than good, the world would have been destroyed with the first sin. The devil is way weaker than God. The fact that people are still here is the proof.
