Those definitions: God is good, satan is evil, are objective. Hereby one can accept the Bible or deny it.
Didn't you mean 'subjective' ? Faith is subjective, there is nothing objective about faith.
I wish I had a dollar for each time I've said, "Hate the sin; not the sinner!" still leaves the individual with hate in their heart. And this is good?
That is what the OP and others are implying, that we hate Satan, for being the merry trickster, for leading us away from the "good" sheep. Me? I'm hard pressed to think of a single thing that I hate. There are a lot of things I dislike, like caraway seeds (*gags*) and liver (*double gag*), but not outright hate.
Well when you take a character out of their own mythology, what do you expect?
No, but the character of Satan is heavily associated with Christianity. One could be forgiven for thinking that this is the Satan in Satanism. The poet Percy Shelley was probably what modern people would call a Luciferian, but he called himself a 'Promethean', which, imo, makes much more sense and takes away any allusion to Abrahamic religion.
Adherents see the character of Satan as an archetype of pride, carnality, liberty, enlightenment, undefiled wisdom, and of a cosmos which Satanists perceive to be motivated by a "dark evolutionary force of entropy that permeates all of nature and provides the drive for survival and propagation inherent in all living things"
That said:
Who the Hell is Satan?
Here's my understanding of this "Old Enemy" as the literary scholar Neil Forsyth coined and what I consider to be the foundation of what is called Satanism.
Satan has always existed, only under other names and guises, Satan is a powerful and primordial archetype of man's psyche . . . a meme, or what some may now call a "Godform", I think the Magus of Chaos, Peter Carroll uses that term?
This archetype is the reflection of how we perceive ourselves in relation to what we call the "others". Satan is a social and cultural phenomenon as old as the mind of humanity itself. There has always and will always, be essentially two worldviews consisting of oppositions and they are "Us & Them" or "Me" and "the rest of you" . . . etc.
Sumerian and Akkadian tablets concur this worldview from the earliest known writings, the ancient Egyptian word for an Egyptian meant "human", which excluded all who were not Egyptian to be relegated to 'non-human', the Greek word for non-Greeks was "barbaroi" (barbarians). The Jewish Essenes called anyone not an Essene "ha satan" (the adversary), Zoroastrianism set forth the dualistic "good" (what we believe in) and "evil" (what they believe in).
"A society does not simply discover its others, it fabricates them, by selecting, isolating, and emphasizing as aspect of another people's life, and making it symbolize their difference"
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William Scott Green (Professor of the history of religion - ancient Judaism, biblical studies, and the theory of religion).
So, who/what is this Satan?
He simply is who you are not!