The ascendancy of Christianity by the fifth century had much to do with this. This is reflected by the Acts of the Apostles, where Paul the Apostle convinces many Ephesians to bring out their magical books and burn them. The language of the magical papyri reflects various levels of literary skill, but generally they are standard Greek, and in fact they may well be closer to the spoken language of the time than to poetry or artistic prose left to us in literary texts. Many terms are borrowed, in the papyri, it would seem, from the mystery cults; thus magical formulas are sometimes called teletai (literally, "celebration of mysteries"), or the magician himself is called "mystagogos" (the priest who leads the candidates for initiation). Much Jewish lore and some of the names for God also appear in the magical papyri. "Jao" for Yahweh, Sabaoth, and Adonai appear quite frequently for example. As magicians are concerned with secrets it must have seemed to many outsiders of Judaism that Yahweh was a secret deity, for after all no images were produced of the Jewish God and God's real name was not pronounced, as the basis of speculation on magic.