Theomancy is defined as the divination by oracles considered being divinely inspired in the ancient world.
Derived from the Greek theos ('god') and manteia ('prophecy') In the Jewish Kabbalah, Theomancy refers to the study of the Majesty of God and the mastery of the sacred names.
The earliest tradition of “oracular” practice in Hellenic culture is from the Archaic period shortly after arrival of the Hellenes in their current place of settlement c. 1300 BC. The oracle was associated with the cults of deities derived from the great goddess of nature and fertility, the preeminent ancient oracle—the Delphic Oracle—operated at the Temple of Apollo at Delphi. Oracles were thought to be portals through which the gods spoke to man. In this sense they were different from seers (manteis in Greek) who interpreted signs sent by the gods through bird signs, animal entrails, and other various methods.
According to “An Encyclopedia of Occultism” by Lewis Spence, the one who possesses the science knows the future, commands nature, has full power over angels and Demons, and can perform miracles. The Rabbis claimed that it was through Theomancy that Moses performed so many miracles; that Joshua was able to stop the sun; that Elias caused fire to fall from heaven, and raise the dead; that Daniel closed the mouths of lions; and that the three youths were not consumed in the furnace.
Séance is the most popular method of Theomancy where a group of persons allegedly contact and receive messages from discarnate beings or spirits of the dead.
In Voodoo, participants believe that spirits or loas come to visit the ceremony, by taking possession of individuals and speaking and acting through them.