Greek religion is the polytheistic religion practiced in ancient Greece in form of cult practices, thus the practical counterpart of Greek mythology. Within the Greek world, religious practice varied enough so that one might speak of Greek religions. The cult practices of the Hellenes extended beyond mainland Greece, to the islands and coasts of Ionia in Asia Minor, to Magna Graecia (Sicily and southern Italy) and to scattered Greek colonies in the Western Mediterranean, such as Massilia (Marseille). Greek examples tempered Etruscan cult and belief to inform much of the Roman religion.
It is perhaps misleading to speak of "Greek religion" as a unified system of dogma or ritual; perhaps the most conspicuous aspect of the religions practised in the Greek city states is their variety. Different cities worshipped different deities; Athens had Athena; Sparta, Artemis; Corinth was a center for the worship of Aphrodite; Delphi and Delos had Apollo; Olympia had Zeus, and so on down to the smaller cities and towns. Identity of names was not even a guarantee of a similar cultus; the Greeks themselves were well aware that the Artemis worshipped at Sparta, the virgin huntress, was a very different deity from the Artemis who was a many-breasted fertility goddess at Ephesus. When literary works such as the Iliad had conflicts among the gods because their followers were at war on earth, these conflicts were a celestial reflection of the earthly pattern of local deities. Eventually, the worship of major deities spread from one locality to another, and most larger cities boasted temples to several major gods; the identification of different gods with different places remained strong to the end.
The variety in Greek religion is also caused by the long history of Greece. Greek religion spans a period from Minoan and Mycenean periods to the days of Hellenistic Greece and its ultimate conquest by the Roman Empire. Religious ideas continued to develop over this time; by the time of the earliest major monument of Greek literature, the Iliad attributed to Homer, a consensus had already developed about who the major Olympian gods were. Still, changes to the canon remained possible; the Iliad seems to have been unaware of Dionysus, a god whose worship apparently spread after it was written, and who became important enough to be named one of the twelve chief Olympian gods.
In addition to the local cults of major gods, various places like crossroads and sacred groves had their own tutelary spirits. There were often altars erected outside the precincts of the temples. Shrines like hermai were erected outside the temples as well. Heroes, in the original sense, were demigods or deified humans who were part of local legendary history; they too had local hero-cults, and often served as oracles for purposes of divination. What religion was, first and foremost, was traditional; the idea of novelty or innovation in worship was out of the question, almost by definition. Religion was the collection of local practices to honour the local gods.
The most widespread public act of worship in ancient Greece was sacrifice, especially the blood sacrifice of animals. The temples of the Greek religion generally were not public gathering places where people gathered socially for collective indoor prayer; most temples were little more than boxes that held a cult idol of the deity. Rather, the temples were part slaughterhouse and part barbecue; oxen, sheep, horses, swine, dogs, various birds, and almost every kind of beast, be it fur, fish, or fowl, were offered as sacrificial victims to one deity or another, again depending chiefly on local custom. When we are told in studies of mythology that "horses are sacred to Poseidon" or roosters to Hermes, what this meant first and foremost was that these animals were customarily offered as sacrifices to those gods. Most sacrificial victims were food animals; for these, the usual practice was to offer the god the blood, bones, and hide of the victim, while the worshippers kept and ate the rest.
Votives were gifts offered to the gods by their worshippers. They were often given for benefits already conferred or in anticipation of future divine favors. Or they could be offered to propitiate the gods for crimes involving blood-guilt, impiety, or the breach of religious customs. They could be given either voluntarily or in response to demands by the cult's priesthood that the donor fulfill a religious vow or honor some religious custom.
Votives were kept on display in the god's sanctuary for a set period of time and then were usually ritually discarded. Bronze tripods, prize cauldrons and figurines, terracotta tablets and figurines, lamps, and vases are typical examples. Armor, weapons, jewelry and other more personalized items were dedicated in large numbers, along with marble statuettes and reliefs. Some of the healing sanctuaries housed replicas of body parts donated in thanks for or in hope of cures. Large sculptural monuments in bronze, marble and other costly materials were routinely dedicated by either private donors or individual city-states in the great Panhellenic sanctuaries like Olympia and Delphi.
The Roman formula expressed the attitude of worshippers to their gods in the formula do ut des; I give sacrifices, so that the god will reward me in return. Public worship was aimed at pleasing the gods so that the gods would send rain, good harvest, military victories, and other public blessings. Private sacrifice was offered for personal goals. Prayer was highly formulaic and ritualized. Most places did not have professional full-time clergy; priests were local officials whose priesthoods were not full time jobs. Major religious sites such as the oracles of pilgrimage brought in enough spiritual tourism to need a full time clerical staff.
Theology did not come naturally to a faith this diverse and essentially local. At the time of the Homeric epics, the Greeks were familiar enough with their neighbours to be aware that the next city-state over worshipped a different subset of gods. The Homeric Hymns tell us something about the belief and worship of various gods, but apart from the (often variable) family trees of the gods, there is little attempt to provide an overarching system of belief.
One of the earliest attempts to give a theology to the Greek religion is found in the works of the poet Hesiod, whose Theogony provides a creation myth focusing on deified abstractions like Night and Time. The decision as to which deities were considered major enough to number among the Twelve Olympians who were the chief gods of the pantheon was no doubt a political decision, at least in part. Because most of the gods were originally local, and inconsistent stories were told of them from one locality to another, the faith of the ancient Greeks resisted systematization, at least at first. Socrates and other philosophers were accused of atheism by the populists of Athens when they pointed out the difficulties in accepting the received ideas about the gods as a whole. Yet Socrates' view of the gods was ultimately to triumph; as time went on, the traditional piety of the sacrificial rites tended to be dismissed as a sort of folklore, while those who were philosophically minded tended to believe in abstract, remote, and genteel gods who vaguely acted to uphold social norms and public virtues.
The virtues fostered by Greek religion were chiefly respect for the gods, who were majestic (sebastos, σεβαστος) and sublime (semnos, σεμνος) Given the variety of rituals and traditions in the Greek religious state, the believer was obliged to hold the faiths of his neighbours in a similar regard to those of his own city. Those who broke the boundaries of the sacred were considered to be rendered impure thereby. These rules held even in the absence of other circumstances; for example, Orestes was pursued by the Furies for the murder of his mother Clytemnestra to avenge her murder of his father Agamemnon, even though Orestes slew him in what he considered to be his duty. Still, the sacred boundaries and laws must be upheld, and Orestes was unable to win free from the Furies until he was absolved by Athena and performed a quest imposed by Apollo.
Syncretism was an essential feature of Greek paganism. Hellenistic culture in the age that followed Alexander the Great was itself syncretic, essentially a blend of Persian, Anatolian, Egyptian (and eventually Etruscan-Roman) elements within a Hellenic overall formula.
Late in the history of classical religion, the Neo-Platonists and the Roman emperor Julian attempted to organize classical paganism into a systematic belief system, which they gave the name of HellÍnismos to: the belief system of the Greeks. Their failure to do so stemmed from the essentially local and traditional nature of the religion they sought to protect. Since classical paganism even at that late date was chiefly a matter of following a local tradition, rather than commitment to an overarching belief system and body of doctrine, their rear-guard attempt to create an overarching structure or body of doctrine came too late.
Julians vision of a synthesis of Platonism and Hellenism was taken up in the 14th century by George Gemistos Plethon, a forerunner of the Renaissance.
Julians vision has also, in modern times, become the starting point of Greek Reconstructionists who also call their religion Hellenismos.
Those whose spiritual leanings were not satisfied by the public cult of the gods could turn to various mystery religions. Here, they could find religious consolations that the traditional cultus could not provide: a systematic religious doctrine, an attractive afterlife, a communal worship, and a band of spiritual fellowship. Some of these mysteries, like the mysteries of Eleusis and Samothrace, were ancient and local. Others were spread from place to place, like the mysteries of Dionysus. During the Hellenistic period and the Roman Empire exotic mystery religions like those of Osiris and Mithras became widespread.
As early Christians rose to political power, the public aspects of Greek religion and culture were systematically exterminated, plunging Europe into the Dark Ages. The religion survived only in rural areas to be periodically revived.
The European renaissance was primarily the rediscovery and reintroduction of the culture and learning of ancient Greek religion and society by western Europe.
Many neo-pagan religious paths, such as Wicca, use aspects of ancient Greek religions in their practice; Greek reconstructionism or Hellenismos focuses exclusively thereon.
The vast majority of modern Greeks are Greek Orthodox.
- Walter Burkert, Greek Religion. Boston: Harvard University Press, 1987. ISBN 0674362810. Widely regarded as the standard modern account.
- Jane Harrison, Prolegomena to the Study of Greek Religion, 1903. An early classic, against which many modern accounts have reacted.
- Karl Kerenyi, The Gods of the Greeks
- Karl Kerenyi, Dionysus: An Archtypical Image of Indestructible Life
- Karl Kerenyi, Eleusis: Archtypal Image of Mother and Daughter. The central modern accounting of the Eleusinian Mysteries.
- Jon D. Mikalson, Athenian Popular Religion. Chapel Hill: University of North Carolina Press, 1983. ISBN 0807841943.
- Robert Parker, Athenian Religion: A History Oxford: Clarendon Press, 1996. ISBN 019815240X.