Neither The Satanic Temple nor Church of Satan actually believe in a literal personality known as the devil.

They're mainly theater nerds trolling self-righteous religiots and making it up as they go along.

The Satanic Temple's main mission is enforcing the separation of church and state by pointing out the hypocrisy of giving a single superstition official preference, in violation of the 1st Amendment. 

Interestingly enough however, if you research the pre-biblical origins of the Melek Taus/Enki/Lucifer/Shaitan/Satan myth, you find a character defined as "evil" solely for opposing "God"... on behalf of mankind. The version subscribed to by modern satanists is simply an archetype of individuality and rebellion against an oppressive system. They also promote basic respect and good manners. 

Any religion that views the acquisition of knowledge as "evil" needs to be reevaluated. If you can't, consider yourself brainwashed.