The purpose of oracles in Greek mythology, particularly the Oracle of Delphi, was to provide divine guidance and prophecy. Individuals and city-states would consult the oracle, often represented by the priestess Pythia, who delivered cryptic messages believed to be inspired by the god Apollo. These prophetic insights influenced important decisions, ranging from personal dilemmas to political strategies, highlighting the role of divine communication in human affairs and the quest for knowledge about the future.