Satan is pure spirit. He often appears as something else, to mislead. He appeared to Padre Pio as Jesus, to frighten him. He sometimes appears as a raging animal.
The ritual of exorcism is not practiced by an ordinary priest. An exorcist requires specific training and must be thought to have a personal sanctity. He can be exposed to dangerous behavior and personal threat. His prayers often cause a violent response as he attempts to shine a beam of light into the darkness.
When I am told (by those who confuse predestination with God's providence) that God already knows who will be saved and who will be damned, and therefore anything we do is useless, I usually answer with four truths that the bible spells out for us:God wants that everyone be saved; No one is predestined to go to hell; Jesus died for everyone; and everyone is given sufficient graces for salvation.