He never asks to come, and he never wants to leave. And he's really no guest at all.
What he wants is to burrow into your brain, like a bad virus. He'd be very content to short circuit your hardware in your head. His ultimate desire, though, is your complete destruction.
There're many names for him: The Prince of Darkness, Father of Lies, Satan, Lucifer and the Devil are a few titles. He is the enemy of our souls, slick and cunning, deceitful and alluring. He's no more than a thief and a killer, certainly not your impish pal in a red suit with a pitchfork.
He'd love it if you never believed in him at all, just as equally as he'd love you to be obsessed with him, finding his dark, sadistic image to be cool and a counterculture phenomenon.
I've been a target of his schemes because I believe in God and in the sacrifice of Jesus on the cross for our salvation. Being targeted goes for anybody that gets on his case. Too many people believe his lies, believe that they are of no real value or that God is either nonexistent or not good.
So to my unwelcome house guest... you cannot have my soul. I am a child of God. Therefore, God has the final say, and He says that I am valuable, and that I am here for His good purposes.