Demon
The contemporary Roman Catholic Church unequivocally teaches that angels and demons are real beings rather than just symbolic devices. The Catholic Church has a cadre of officially sanctioned exorcists which perform many exorcisms each year. The exorcists of the Catholic Church teach that demons attack humans continually but that afflicted persons can be effectively healed and protected either by the formal rite of exorcism, authorized to be performed only by bishops and those they designate, or by prayers of deliverance, which any Christian can offer for themselves or others.
Mark 1
There were several people who were claimed to have the ability to perform exorcisms in the ancient world and many ancient opponents of Christianity dismissed Jesus as just another magician. Most descriptions of exorcisms at the time tended to involve the exorcist tricking the spirit or demon into leaving the victim by convincing them the exorcist had more power than the being, not a method Jesus employs. Parallels in Hellenistic cultural stories of exorcisms differ in that they usually involve an associated disease, which is not the case here. John P. Meier sees a clear distinction between these incidents and descriptions of magicians at the time.