The image of Satan was not actually created until the Roman Catholics and other religions, used the image of a Celtic diety, Cernunnos, and the Greco-Roman diety, Pan. They used these two dieties to form there image of the Devil (Satan). They taught that the devil was evil and therefore that anyone who worshiped the horned gods, were evil. The idea of the Satan was never actually introduced until centuries after Jesus. In the OT there is no actual evidence of this 'Satan'. Instead there is the 'the accuser' who is introduce in the OT. Who has many times placed certain followers to a test. (i.e. Job) It also states in Isaiah that the morning star was sent to the pit. The pit is where the wicked are sent after death until the coming of the true Messiah. There is no actual proof of torture in the pit or hell, until the NT. He was stripped of his powers and cast into the pit as any wicked ruler from Earth is. So there is no actual fighting between them, and no proof of the belief that there will be some type of fight between good and evil at the coming of the Messiah.