Sentence:  For instance I have heard many people say that Dionysus was a mortal man because he was born of Semele, and that he became a god through his knowledge of <WSD>theurgy</WSD> and the Mysteries, and like our lord Heracles for his royal virtue was translated to Olympus by his father Zeus. 
Meaning of the word marked with <WSD> tags:  A form of magic designed to allow for worship or conjuration of, or communication with spirits or deities.