Satan exists, of that I am certain. But that is because for me, and according to most strands of the Jewish tradition, Satan is not some little guy with a pointy tail and a pitch fork. Though versions of that devil can be found, especially in the mystical tradition, it’s not the norm. And even if it were, I would still have no fear of a Devil who leads the forces of evil in an ongoing battle against God and the angels.
Actually, that kind of dualism should be hard for any monotheist to maintain. But the need to personalize the evil we do face in the world is apparently so powerful, that lots of folks give in to that temptation — double entendre intended. It’s either that, or they simply cannot stomach a god who would “allow” so many awful things to go on in “His” world. They prefer a smaller god locked in battle with the red guy and his minions.
But evil is real….

Evil is real. It’s the opposite of whatever we hold most dear and sacred. It’s that which undermines our highest values and our commitment to human dignity and life. Evil is, as the Oxford English Dictionary defines it, “the most comprehensive adjectival expression of disapproval, dislike, or disparagement.” But it’s not separate from God.
In fact, there was even a time in a previous millennium, when Jewish liturgy had the courage to praise God “who fashions the good and creates evil.” And that is where Satan enters the picture. Satan is the tempter and the accuser, who both seduces us into making the choice for evil over good and then confronts us with the damage of the choices we make.
So, Satan is found when war is tried before peace. Satan is found when we build religious and political identities and loyalties based more on the hate of what we are not, than the love of what we are. Satan is found when I give in to a pizza or a box of doughnuts, even though they may put me in an early grave.
No they are not all equally dangerous, but they all represent the same dynamic of making choices which undermine our own best values. So ironically, if we talked less about “EVIL” and the Devil, and more about how to make those choices of which we would end up being the most proud, we could take on the Satans with whom we all struggle, and evil and the devil would pretty much be taken care of.