Prominent secular and atheist commentators have argued lately that religion "poisons" human life and causes endless violence and suffering. But the poison isn't religion; it's monotheism. The polytheistic Greeks didn't advocate killing those who worshiped different gods, and they did not pretend that their religion provided the right answers. Their religion made the ancient Greeks aware of their ignorance and weakness, letting them recognize multiple points of view.
There is much we still can learn from these ancient notions of divinity, even if we can agree that the practices of animal sacrifice, deification of leaders and divining the future through animal entrails and bird flights are well lost.
My Hindu students could always see something many scholars miss: The Greek gods weren't mere representations of forces in nature but independent beings with transcendent powers who controlled the world and everything in it. Some of the gods were strictly local, such as the deities of rivers and forests. Others were universal, such as Zeus, his siblings and his children.
Zeus did not communicate directly with humankind. But his children -- Athena, Apollo and Dionysus -- played active roles in human life. Athena was the closest to Zeus of all the gods; without her aid, none of the great heroes could accomplish anything extraordinary. Apollo could tell mortals what the future had in store for them. Dionysus could alter human perception to make people see what's not really there. He was worshiped in antiquity as the god of the theater and of wine. Today, he would be the god of psychology.
Zeus, the ruler of the gods, retained his power by using his intelligence along with superior force. Unlike his father (whom he deposed), he did not keep all the power for himself but granted rights and privileges to other gods. He was not an autocratic ruler but listened to, and was often persuaded by, the other gods.
Openness to discussion and inquiry is a distinguishing feature of Greek theology. It suggests that collective decisions often lead to a better outcome. Respect for a diversity of viewpoints informs the cooperative system of government the Athenians called democracy.
Unlike the monotheistic traditions, Greco-Roman polytheism was multicultural. The Greeks and Romans did not share the narrow view of the ancient Hebrews that a divinity could only be masculine. Like many other ancient peoples in the eastern Mediterranean, the Greeks recognized female divinities, and they attributed to goddesses almost all of the powers held by the male gods.
The world, as the Greek philosopher Thales wrote, is full of gods, and all deserve respect and honor. Such a generous understanding of the nature of divinity allowed the ancient Greeks and Romans to accept and respect other people's gods and to admire (rather than despise) other nations for their own notions of piety. If the Greeks were in close contact with a particular nation, they gave the foreign gods names of their own gods: the Egyptian goddess Isis was Demeter, Horus was Apollo, and so on. Thus they incorporated other people's gods into their pantheon.
What they did not approve of was atheism, by which they meant refusal to believe in the existence of any gods at all. One reason many Athenians resented Socrates was that he claimed a divinity spoke with him privately, but he could not name it. Similarly, when Christians denied the existence of any gods other than their own, the Romans suspected political or seditious motives and persecuted them as enemies of the state.
The existence of many different gods also offers a more plausible account than monotheism of the presence of evil and confusion in the world. A mortal may have had the support of one god but incur the enmity of another, who could attack when the patron god was away. The goddess Hera hated the hero Heracles and sent the goddess Madness to make him kill his wife and children. Heracles' father, Zeus, did nothing to stop her, although he did in the end make Heracles immortal.
But in the monotheistic traditions, in which God is omnipresent and always good, mortals must take the blame for whatever goes wrong, even though God permits evil to exist in the world he created. In the Old Testament, God takes away Job's family and his wealth but restores him to prosperity after Job acknowledges God's power.
The god of the Hebrews created the Earth for the benefit of humankind. But as the Greeks saw it, the gods made life hard for humans, didn't seek to improve the human condition and allowed people to suffer and die. As a palliative, the gods could offer only to see that great achievement was memorialized. There was no hope of redemption, no promise of a happy life or rewards after death. If things did go wrong, as they inevitably did, humans had to seek comfort not from the gods but from other humans.