Well, if you want to talk about "Satan" specifically, there have been books written on his evolution throughout the Bible to become the kind of figure he is known as today. The fact he "evolved" throughout the literature suggests he is a concept and not a fact.
I tend to see "evil" as a way of behaving rather than as a "person" or "thing," though. There might be specific individuals who are the epitome of evil, but it doesn't mean that Evil exists as an entity.
You also need to apply human morality to reach our definition of evil. Animals without capacity for moral choice are not evil, for example. If a bear eats you, it's not because the bear wanted to murder and expunge you, it is because the bear was hungry or you are encroaching on its territory, and it is reacting out of survival instincts. Interestingly, we expect people to behave differently, even if they think they are operating out of survival; love is the capacity to treat another as if they were yourself, rather than viewing them as "Other" and thus an enemy or parasite. In general, evil seems to be like a black hole, force that has imploded upon itself so that its world is only as big as itself and no other entities are caught inside the event horizon to be viewed as kin. Everything is a threat or food; everything is an enemy or prey; there is only the self, and the self cut off from community soon becomes lost on its own private wasteland.
Hence, evil is imploding, isolationist, aggressive, and destructive.
What's this? What's this? Can it be? Did Christmas come early this year?? Oh gee!Yup. About the standard of replies I expected.
Going to stop posting threads.