I'm sure you believe God is perfect. He's never made a mistake, and everything was within his plan. I'm sure you'll say even his mistakes are within a plan after I'm done. Lets start with creation. Or well, the belief of it.
God creates earth. But why? Maybe he's lonely. I doubt he just wanted to make people. I believe he was lonely anyway. Lonely=Negative emotion. So he creates us, etc etc. (Go along with it.) and then Eden rolls along. Why would he create evil? Why create an evil tree, and the Snake, unless he had to? If God put all of himself into the world and his creation, then that means he is evil. Evil stuck, and evil took over. He had a flaw within himself. And if he was perfect, he would have undone this damage. But he couldn't, simply because he can't change himself. Right?
Anyway. Satan. The story goes he let Satan believe all God believed, and saw. Immediately Satan turned into, jealous, angry and confused. ...Well? Whats that show us? God has a war raging within himself, or he's like the rest of us. And literally did make us in his image, with all emotions. Including evil.
God can undo death, but he can't kill demons. He "Casts them out" and they go elsewhere and mostly into other people. But why? Because there has to be evil, thats how he created it. Death isn't evil, its good. Therefore he can change it.
I have more, but I'll let you think about that.