Exorcism
In Catholic practice the person performing the exorcism, known as an exorcist, is an ordained priest. The exorcist recites prayers according to the rubrics of the rite, and may make use of religious materials such as icons and sacramentals. The exorcist invokes God—specifically the Name of Jesus—as well as members of the Church Triumphant and the Archangel Michael to intervene with the exorcism. According to Catholic understanding, several weekly exorcisms over many years are sometimes required to expel a deeply entrenched demon.
Exorcist
The Eastern Churches did not establish a minor order of exorcist, but simply recognised the calling of lay or ordained members of the faithful who had the appropriate spiritual gifts. In principle, every Christian has the power to command demons and drive them out in the name of Christ.