I found an interesting link to something I talk about a lot, probably too much, but I find it highly interesting.
This is mankind's true religion. This is the religion ALL humans partake of. It is made up of the little fishbowl sects with names like Buddhism, Christianity, and Islam.
Unknown to most "normal" humans (who cannot see the bigger picture), all of mankind's religions are based on Astrology and the movements of the sun. This is something that was developed way back in the hunter-gatherer days as a means to ensure the survival of our race. A way to organize the primordial chaos which ruled man's early world. Important facts about the seasons, hunting, planting, and harvest times were rolled into mythic ritual and allegory and passed down through the generations to ensure their survival and prosperity. It was basically "cave-man science", or the nearest equivalent they could come up with.
As society advanced, it gradually took on organization, and was shaped into a myriad of different deities depending upon the culture at hand. These religions rose and fell, each copying the structure of the last and changing the cultural setting of the heroes and deities. The old deities becoming the devils of the new. The ruling classes learned they could control and pacify their populations with threats of eternal torment, and societal controls were then worked into the mix.
All of these religions retained the same core elements (things like the holy trinity, calendar and holidays, etc) with the difference being largely cultural. This is why we have all the major holidays occurring within three days of events such as the various Solstices' or equinoxes almost universally. It is also why we have similar stories, such as "the Great Deluge" and the resurrecting saviour being found in cultures as widely separated as the ancient Sumerians and the Native Americans who could not have possibly had direct contact. Religions such as Islam were later offshoots and founded after this syncretism occurred, but there are still broken elements of it to be found.
Alas, all this has been forgotten by most of mankind. They are too busy fighting and arguing that their version is the only true religion, though they are really all brothers under the same Sun. The original reason for the religion has been lost, and it has been replaced with basically empty dogma, in many cases. There are lots of fervent believers, but most really do not truly comprehend anything about what it is all about, or how mind-shatteringly large and old it really is. They can see lots of little trees, but are missing the giant forest that the trees comprise. It is sad really, because what was intended to help man live a better life, now entraps him in a constant cycle of war and deprivation.