Hunter/gatherer animism. The best developed and most respected knowledge of primitive hunter/gatherer cultures was the knowledge of plants and animals. The world of plants and animals, then, provided these cultures with their most complex, most meaningful set of metaphors. They made use of these metaphors in their religion by creating rituals in which humans took on the roles of plants or animals and by telling explanatory stories about plant and animal spirits.
Agricultural Earth worship. Agricultural society demanded more social structure and provided a new and richer source of metaphors. The Earth as Great Mother took precedence over all other beings, and her yearly cycle of birth and death was the fundamental cycle of society. Time itself was imagined as a cycle, and the annual festivals did not simply re-enact the first planting or the first harvest, they invoked the eternal planting and the eternal harvest, which was and is and is to be.
City-state polytheism. Civilization created a multiplicity of roles in addition to those of farmer or hunter--potter, warrior, merchant, metal-worker and a host of others. Trade arose, and with it debts that could not be settled or canceled in a single year. The classical pantheons of antiquity developed to meet these needs, along with a notion of linear time (or cyclical time with an unimaginably long cycle). The new sciences of mathematics and astronomy provided a model for these ideas by charting the motions of the visible planets. The planets of astrology, like the classical gods and the diverse human roles, kept each to its own cycle. The configuration of all the planets repeated, if ever, in a cycle that was incalculably long. As above, so below.
Imperial monotheism. The unification of city-states into empires presented new challenges, and gave prominence to a new kind of knowledge, the knowledge of government. The warrior, the ruler, the law-giver--these roles took precedence over all other social roles, and throughout the Mediterranean ancient storm gods were replaced by a new vision of the divine: the Sky Father. Wielding the thunderbolt of war, watching from on high, and handing down his judgments from the mountain tops, the Sky Father came to dominate pantheon after pantheon.
In Persia a parallel development was taking place, as the dualistic vision of Zoroaster provided a new way for diverse peoples to be united. The world was portrayed as a battleground in the war between the Gods of Light and Darkness, of Truth and Lie. The Zoroastrian mythology told of a primordial perfection that had been corrupted by darkness, but which would be restored again at the end of time. Whatever their languages or cultures, people could join together in the cause of Light and Truth, and share in the ultimate victory. These two tendencies came together in Judaism (possibly during the captivity of the Jews in Babylon), creating a new monotheistic vision that eventually would dominate Rome as Christianity and the Near East as Islam.
Medieval Catholicism. Politics remained the dominant metaphor for religion in Europe through the Middle Ages, but the political reality changed drastically with the collapse of Rome. The doctrine of the Trinity split the Godhead as the Empire itself was splitting between East and West. And as the Western Empire splintered into countless feudal fiefdoms, each came to be protected by its own patron saint. Saints also became patrons of the various arts and trades, restoring much of classical paganism under the monotheistic umbrella of Christianity. The Catholic God (like his Pope in Rome) was all-powerful but remote, and daily life became the province of the pantheon of saints.
Design monotheism. The dream of Rome reunited was never fulfilled, and yet monotheism rose again. In part this was due to the old political imagery, as the fiefdoms began to unite into nations and the doctrine of the divine right of kings developed. But the monotheistic revival of the Reformation contained a new element as well, one that became increasingly important with time. This was a new set of metaphors centering on mechanics and design. The universe was envisioned as a vast clockwork created by a Great Designer, operating under the Designer's simple but abstract laws. This vision motivated the search for unifying principles, and made possible the rise of science. In turn the success of scientists in finding such unifying principles argued powerfully for the correctness of the vision. Newton's stunning explanation of all motion in terms of three mathematical laws crowned this process, and the effects of this achievement rippled out into all fields of thought. (When Jefferson sought to justify American independence in his Declaration, he did not back his argument with the authority of scripture as Luther might have done. Instead he argued in the style of Newton, making deductions from abstract but "self-evident" principles attributed to God.) The significance of this mechanistic metaphor grew with the Industrial Revolution. Machines became an essential part of daily life and were an increasing source of social and economic power for those who could invent, own, or operate them. It became natural to describe any strange or complex phenomenon in mechanistic terms. Roosevelt's New Deal spending "primed the pump" of the American economy, but a constriction of credit might cause it to "throttle back". Behaviorism applied the mechanistic metaphor to human consciousness, and determinism argued that every particle in the universe had a unique and determinable future.
This summary illustrates several points. First, at any given point in history there is a central metaphor, a field of thought which provides the images and vocabulary for a culture's religious expression. This field of thought--be it hunting, agriculture, politics, or physics--may have no explicit religious content of its own, but the images and concepts that it provides have a profound effect on the religion of its time. Second, there seems to be no clear evolutionary trend toward one set of beliefs or away from another. Sometimes monotheism succeeds polytheism, for instance, and sometimes the reverse is true. The beliefs themselves mean different things at different times, depending on the underlying metaphors that describe them. The Sky Father of ancient times, for instance, both is and is not the same being as the "Divine Providence" of the Puritans, while the Christian Devil both is and is not the Zoroastrian God of Darkness. Third, the remnants of all these epochs are still with us. The bunnies and eggs of Easter go back to the agricultural cycle, while the Eucharist is a remnant of animistic magic. The Great Mother lives on as the Catholic Madonna and has recently been reborn as the Gaia hypothesis. Old religious institutions may be extinguished, but the underlying beliefs seldom are. Their seeds are deep in the cultural loam, and even after centuries of weeding and spraying you will still find them springing up in the back corners of the garden. Finally, and most importantly, a religion is not just a set of beliefs about God or the gods. A religion provides a complete vision of life, humanity, and how the universe works. God is only one of many characters in the story that a religion tells. As our knowledge grows and our needs change, we have both the opportunity and the necessity of telling the story in a new way.