Satanism is just a name and the name is influenced by the fictional character of satan. ( what they believe to be fictional )
Like…some people name their bands after fictional characters as its a representation. They dont actually beleive in it, its all metaphorical.
I named my dog deano after the dinosaur in the flintstones because they both have long tongues and pounce on you.
I dont actually believe the dinosaur in the flintstones is real.