Ancient Greek religion
Religious practices in ancient Greece encompassed a collection of beliefs, rituals, and mythology, in the form of both popular public religion and cult practices. The application of the modern concept of "religion" to ancient cultures has been questioned as anachronistic. The ancient Greeks did not have a word for 'religion' in the modern sense. Likewise, no Greek writer is known to have classified either the gods or the cult practices into separate 'religions'. Instead, for example, Herodotus speaks of the Hellenes as having "common shrines of the gods and sacrifices, and the same kinds of customs".
Most ancient Greeks recognized the twelve major Olympian gods and goddesses—Zeus, Hera, Poseidon, Demeter, Athena, Ares, Aphrodite, Apollo, Artemis, Hephaestus, Hermes, and either Hestia or Dionysus—although philosophies such as Stoicism and some forms of Platonism used language that seems to assume a single transcendent deity. The worship of these deities, and several others, was found across the Greek world, though they often have different epithets that distinguished aspects of the deity, and often reflect the absorption of other local deities into the pan-Hellenic scheme.
The religious practices of the Greeks extended beyond mainland Greece, to the islands and coasts of Ionia in Asia Minor, to Magna Graecia, and to scattered Greek colonies in the Western Mediterranean, such as Massalia. Early Italian religions such as the Etruscan religion were influenced by Greek religion and subsequently influenced much of the ancient Roman religion.
Beliefs
"There was no centralization of authority over Greek religious practices and beliefs; change was regulated only at the civic level. Thus, the phenomenon we are studying is not in fact an organized "religion". Instead we might think of the beliefs and practices of Greeks in relation to the gods as a group of closely related "religious dialects" that resembled each other far more than they did those of non-Greeks."Theology
Ancient Greek theology was polytheistic, based on the assumption that there were many gods and goddesses, as well as a range of lesser supernatural beings of various types. There was a hierarchy of deities, with Zeus, the king of the gods, having a level of control over all the others, although he was not almighty. Some deities had dominion over certain aspects of nature. For instance, Zeus was the sky-god, sending thunder and lightning, Poseidon ruled over the sea and earthquakes, Hades projected his remarkable power throughout the realms of death and the Underworld, and Helios controlled the sun. Other deities ruled over abstract concepts; for instance Aphrodite controlled love. All significant deities were visualized as "human" in form, although often able to transform themselves into animals or natural phenomena.While being immortal, the gods were certainly not all-good or even all-powerful. They had to obey fate, known to Greek mythology as the Moirai, which overrode any of their divine powers or wills. For instance, in mythology, it was Odysseus' fate to return home to Ithaca after the Trojan War, and the gods could only lengthen his journey and make it harder for him, not stop him.
The gods had human vices and many behaved with arguably less morality than a typical human. They interacted with humans, sometimes even spawning children—called demigods—with them. At times, certain gods would be opposed to others, and they would try to outdo each other. In the Iliad, Aphrodite, Ares, and Apollo support the Trojan side in the Trojan War, while Hera, Athena, and Poseidon support the Greeks.
Some gods were specifically associated with a certain city. Athena was associated with Athens, Apollo with Delphi and Delos, Zeus with Olympia and Aphrodite with Corinth. But other gods were also worshipped in these cities. Other deities were associated with nations outside of Greece; Poseidon was associated with Aethiopia and Troy, and Ares with Thrace.
Identity of names was not 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. Though worship of the major deities spread from one locality to another, and though most larger cities had temples to several major gods, the identification of different gods with different places remained strong to the end.
File:Esculape, Ma 639.jpg|thumb|upright=.8|Asclepios, god of medicine. Marble Roman copy of a Greek original of the early 4th century BCE. Asclepios was not one of the Twelve Olympians, but popular with doctors like Pausanias, and their patients.
Ancient sources for Greek religion tell a good deal about cult but very little about creed, in no small measure because the Greeks in general considered what one believed to be much less importance than what one did.
Afterlife
The Greeks believed in an underworld inhabited by the spirits of the dead. It was ruled by Hades, a brother of Zeus, and was itself sometimes known as Hades. Tartarus was a place of torment for the damned, and Elysium a place of pleasures for the virtuous. In the early Mycenaean religion all the dead went to Hades, but the rise of mystery cults in the Archaic age led to the development of places such as Tartarus and Elysium.A few Greeks, like Achilles, Alcmene, Amphiaraus, Ganymede, Ino, Melicertes, Menelaus, Peleus, and a great number of those who fought in the Trojan and Theban wars, were considered to have been physically immortalized and brought to live forever in either Elysium, the Islands of the Blessed, heaven, the ocean, or beneath the ground. Such beliefs are found in the most ancient Greek sources, such as Homer and Hesiod. This belief remained strong even into the Christian era. For most people at the moment of death there was, however, no hope of anything but continued existence as a disembodied soul.
Some Greeks, such as the philosophers Pythagoras and Plato, also embraced the idea of reincarnation, though this was only accepted by a few. Epicurus taught that the soul was simply atoms which were dissolved at death, so one ceased to exist on dying.
Mythology
Greek religion had an extensive mythology. It consisted largely of stories of the gods and how they interacted with humans. Myths often revolved around heroes and their actions, such as Heracles and his twelve labors, Odysseus and his voyage home, Jason and the quest for the Golden Fleece and Theseus and the Minotaur.Many species existed in Greek mythology. Chief among these were the gods and humans, though the Titans also frequently appeared in Greek myths. Lesser species included the half-man-half-horse centaurs, the nature-based nymphs and the half-man, half-goat satyrs. Some creatures in Greek mythology were monstrous, such as the one-eyed giant Cyclopes, the sea beast Scylla, whirlpool Charybdis, Gorgons, and the half-man, half-bull Minotaur.
There was no set Greek cosmogony, or creation myth. Different religious groups believed that the world had been created in different ways. One Greek creation myth was told in Hesiod's Theogony. It stated that at first there was only a primordial deity called Chaos, after which came various other primordial gods, such as Gaia, Tartarus and Eros, who then gave birth to more gods, the Titans, who then gave birth to the first Olympians.
The mythology largely survived and was expanded to form the later Roman mythology. The Greeks and Romans were literate societies, and much mythology, although initially shared orally, was written down in the forms of epic poetry and plays. The mythology became popular in Christian post-Renaissance Europe, where it was often used as a basis for the works of artists like Botticelli, Michelangelo and Rubens.
Morality
One of the most important moral concepts to the Greeks was aversion to hubris. Hubris constituted many things, from rape to desecration of a corpse, and was a crime in Athens. Although pride and vanity were not considered sins themselves, the Greeks emphasized moderation. Pride only became hubris when it went to extremes, like any other vice. The same was thought of eating and drinking. Anything done to excess was not considered proper. Ancient Greeks placed, for example, importance on athletics and intellect equally. In fact many of their competitions included both. Pride was not evil until it became all-consuming or hurtful to others.Sacred texts
The Greeks had no religious texts they regarded as "revealed" scriptures of sacred origin, but very old texts including Homer's Iliad and Odyssey, and the Homeric hymns, Hesiod's Theogony and Works and Days, and Pindar's Odes were regarded as authoritative and perhaps inspired; they usually begin with an invocation to the Muses for inspiration. Plato even wanted to exclude the myths from his ideal state described in the Republic because of their low moral tone.While some traditions, such as Mystery cults, upheld certain texts as canonic within their praxis, such texts were respected but not necessarily accepted as canonic outside their circle. In this field, of particular importance are certain texts referring to Orphic cults: multiple copies, ranging from between 450 BCE and 250 CE, have been found in various parts of the Greek world. Even the words of the oracles never became a sacred text. Other texts were specially composed for religious events, and some have survived within the lyric tradition; although they had a cult function, they were bound to performance and never developed into a common, standard prayer form comparable to the Christian Pater Noster. An exception to this rule were the already named Orphic and Mystery rituals, which, in this, set themselves aside from the rest of the Greek religious system. Finally, some texts called hierói lógoi by the ancient sources, originated from outside the Greek world, or were supposedly adopted in remote times, representing yet more different traditions within the Greek belief system.