Clearing things up

After someone read my post about evil he said that is sounded like I was saying that God created evil, this isn't what I mean. My answer to the question "if God is all powerful and all good why does evil exist?" according to my definition is this-

"So my conclusion is that because evil is the opposite of good, and good is that which is pleasing to God, evil is that which is displeasing to God, and the reason that evil exists, is because if there is no concept of that which is displeasing to God, there cannot be the concept of that which is pleasing to God, therefore, by creating good the concept of good, the concept of evil was created."

John

P.S. thanks daniel for telling me that it sounded like I meant God created evil just for it's sake :D