Change came from the addition of new religions from other countries, including the Egyptian deities Isis and Serapis, and the Syrian Gods of Atargatis and of Hadad, which provided a new outlet for people seeking fulfillment in both the present life and the afterlife. The worship of Hellenistic rulers was also a feature of this period, most notably in Egypt, where the Ptolemies adopted earlier pharaonic practice, and established themselves as god-kings. Elsewhere rulers might receive divine status without the full status of a God.
Magic was practiced widely, and this too, was a continuation from earlier times. Throughout the Hellenistic world, people would consult oracles, and use charms and figurines to deter misfortune or to cast spells. Also developed in this era was the complex system of astrology, which sought to determine a person's character and future in the movements of the sun, moon, and planets. The systems of Hellenistic philosophy, such as Stoicism and Epicureanism, offered an alternative to traditional religion, even if their impact was largely limited to the educated elite.
Central to Greek religion in classical times were the twelve Olympian deities headed by Zeus. Each god was honored with stone temples and statues, and sanctuaries (sacred enclosures), which, although dedicated to a specific deity, often contained statues commemorating other gods. The city-states would conduct various festivals and rituals throughout the year, with particular emphasis directed towards the patron god of the city, such as Athena at Athens, or Apollo at Corinth.
Religious practice would also involve the worship of heroes, people who were regarded as semi-divine. Such heroes ranged from the mythical figures in the epics of Homer to historical people such as the founder of a city. At the local level, the landscape was filled with sacred spots and monuments; for example, many statues of Nymphs were found near and around springs, and the stylized figures of Hermes could often be found on street corners.
Magic was a central part of Greek religion and oracles would allow people to determine divine will in the rustle of leaves; the shape of flame and smoke on an altar; the flight of birds; the noises made by a spring; or in the entrails of an animal. Also long established were the Eleusinian Mysteries, associated with Demeter and Persephone. People were indoctrinated into mystery religions through initiation ceremonies, which were traditionally kept secret. These religions often had a goal of personal improvement, which would also extend to the afterlife.