First I am going to come at this from several different angles, Tribal, Religious studies, Anthropological and Scientific. This is very generalized to try to make it easier to read for laymen so it may seem a bit simplistic, but it is factual and does apply as is.
WHY IS THERE RELIGION?
I am American Indian and was raised with tribal values which was and is in conflict with American ideology, it is also basis for my humanistic philosophy. In the tribal society I have my upbringing but also have anthropological study of tribal societies to add into this. Early man would have questioned the natural world. Why it was the way it was? What caused it to be this way? Why are we here? Which led to mysticism (spirits) and these spirits then became more powerful beings as the mysticism broadened over time a natural evolution as animism and ancestral worship (spirits) evolve into polytheism (gods). This is how this evolution has been seen to occur.
These natural world questions were unanswerable to early man, until the creation of a mystical world outside our ability to see. This is logical when you put yourself into this situation, as I was myself. Now Originally I was raised Catholic but taught at home Native values of community, family then self this is ultimately the core of who we as Native peoples are humanistically and religiously. Religion follows the evolution of the society it is practiced in, and leaves a pattern easily follow with that evolution.
At first tribes are small, less than 50 people, because they are dependent on food gathering and scarcity of sources, moving constantly is harder on individual members, also Skirmishes (not war) over the food sources, and thus higher mortality rates. There would have been spirits helping the tribe as a whole, praying to individual spirits by the tribe for rain when needed, OR to all the spirits at once. This follows the egalitarian base ideas all members pull together, to work together, and survive AKA egalitarianism or primitive Communism. When the tribe was experiencing hardship the "spirits" were then interpreted by the spiritist (male or female) as being angry. This is the earliest accounts of the spirits demanding atonement for broken agreements (or rules) with the spirits, or between humans, but not necessarily the main rule over these laws, just on occasions.
Soon when the tribe turns toward sedentary society, first with pastoralist (in most cases but sometimes skipped), then to Agrarianism. The spirits would evolve into individual spirits for everything, rain, hunting, etc. How does that happen? The tribe grows larger segmenting into bands then into clans (agrarian), between 50 -150 people in pastoralist societies and greater than 150 people for Agrarian societies. This due to a more stable food sources and roots taking in an area or region. Also because of territorial invasion in these claimed lands (areas/regions) more organized warrior societies develop and war becomes a major issue, by default other societies develop as well thus leading clans and by extension new and more developed laws. This is where the spirits begin to be set as the principal rulers of social laws and rules.
The separation in the tribe for various duties develops, women for gathering as a whole, men for hunting, there was cross over though too, some men gathered, and some women hunted, but groups were assigned specific duties forming Clans thus leading to specific leaders chosen for the various clans or group. Then specific spirits or animals for guides in those clans. Example of clan specificity, would be the clan that took care of the dead and prepared them for their burials, In some North American tribes this was represented by the Owl in the physical realm but a spirit in the incorporeal realm, often referred to as the owl spirit, but this is a mistranslation, that has carried over. Things like this followed a logical path, owls spoke in the night and whispered, death happened most often in the night, and soon became attributed to owl song. THUS Owl became the messenger of death and the physical embodiment of the spirit of the clan (totem) that worked with the dead. Now, when the tribe experiences hardship, at this point, it was based on what hardship specifically, say for example drought. Then one or more "spirits" were angry, the rain spirits and/or the spirit of farming (growing crops), etc.
The next phase in the next stage of evolution of religion is deities. As the specialization is applied more stringently in the various societies, it reflects a higher structure on the religion. Specialization develops in the tribes, one person excels at bow making, one excels arrow making, one excels at arrowhead making, hunting, leather making, etc. etc. Specific leaders are chosen, but over all there is a greater leader or ruler. Following suit the spirits excel and become the principals to their disciplines such as rain and storms (fertility), hunting and war, love and relationships, etc. This can be seen most prevalently in the development of state over agrarian clan societies. Examples of this are Mayan, and Aztec Cultures developing separate empire states in the New World, and in the Old World, ancient Egyptian, ancient Greece thus leading to ancient Rome. Along with this more developed centralized government a more developed and centralized religion follows. The early hierarchy in the religious master with apprentices, become titled positions exactly like their state counterparts in government, high priest(ess), priest(ess), and monks or devotees. The deities are the final word on laws as when it comes to rules, man now sets and creates most of them but they are still based traditionally off the original rules of the gods. Any laws set by man is trumped by the original laws of the gods (spirits)
This is not conjecture, but clear facts, from the various American Indian and world tribal cultures, with traceable heritages, and is easy to understand for one as PART of a tribe as well as one who studies the tribes.
The evolution of monotheism does have several separate occurrences but principally are exactly the same because a choice is made. But ultimately it still comes down to a POLYTHEISTIC religion evolving into a MONOTHEISTIC religion. There are two examples I will give before going to the Abrahamic faith.
One of the earliest credited monotheistic faiths was Zoroastrianism from Iran sometime before the 6th century BCE. Based off of the teachings of one man who become the prevalent religious leader of his time. He created, taught, and preached, from the position of leadership of one (himself) and lead to the teaching of one creator. In Zoroastrianism the creator was good and not evil came from him (god). Evil comes as a force bend on destroying creation (devil) and a force trying to maintain it (god). this is the earliest diagram laid out for monotheism in the middle east and many parallels from Zoroastrianism appear in the Abrahamic faith including the clear parallel to god and its status (creator, maintainer, good fighting evil). So One man creates the religion and one god rules over creation.
The earliest monotheism is solidly recorded monotheism in Egypt was the Aten cult under the pharaoh Akhenaten (Amenhotep IV) . He abandoned the traditional polytheistic religion of Egypt for a monotheistic. His principal goal was to centralize his rule and familial control over Egypt, by proclaiming one creator over all Aten (the Sun) and aspect of Ra, but ultimately a combination of Ra, Horus, and Aten. Then he proclaimed the he and his descendants were the embodiment of Aten on earth. It failed in the end as one because of Ahkenatens tyrannical rule made the faith unpopular and he died leaving a young heir who changed the religion BACK to the original polytheism. Coincidentally the sun in Zoroastrianism was gods eye. Again one man creates the religion and one god rules over creation.
Abrahamic faith, is different in that one man did NOT create the faith. The Hebrew tribes had become sedentary (Recall the explanation of sedentary tribes above) and with this new society came war. the Hebrew were constantly t war in the area they settle as at the time it was a narrow region of land that could be settled with a huge diversity of culture and tribal life, we have seen similar examples of this diversity in a small region in the California coastal areas. As the Hebrew people were constantly bombarded with raids and warfare they congregated together for more solid protection under a unified banner and thus the great tribe of the Hebrew people were formed. During this time they were a polytheistic faith and many gods were prayed to, but they were constantly losing battles, it was decided by the leaders that one of the gods needed to be chosen as their main god. They chose not the strongest war like god, but the one god that was known as a protector of the people. The choosers, chose their god, thus becoming the chosen people of that god, Yahweh. So we have the birth of the monotheistic Abrahamic faith, from a polytheistic one, this is well documented.
So far I have mentioned tribal and anthropological, touching on religious studies. Now I go to the scientific, touching on religious studies and biological anthropology aspects. Biologically, we have developed, a region of the brain, that is highly active in religious settings and scenarios. This region of the brain has been mapped and studied and proven to be hyper active during, prayer, meditation, vision questing, and many other various religious related ceremonies and practices. When speaking in tongues or feeling the presence of spirits, or god. When seeing visions or hearing the word of god/spirits speaking to them. All can be attributed to the same region of the brain. It has also been mapped as the SAME region that allows for artist and writers to create internalized imagery of the world or worlds they are creating on canvas when painting or on paper (drawing or writing). There is a drawback however in that it is also the same region that allows for the mental disorders of delusion and schizophrenia. (Research Neurotheology for more detail)
This is the path for how and why religion exists as it stands today, the meanings and development ultimately leading to why it persisted to its present forms. But there was a second question.
IS IT NECESSARY?
The answer is simple once you take into account the evolution of religion. That SINCE religion is an aspect of human creation, coinciding with the evolution of human society, to a point. Then NO religion is no longer necessary, in that as society has evolved, religion was becoming more marginalized with humans creating their own laws and depending on their own moral values learned through humanistic means. Religion adapted as society adapted mainly to keep itself relevant to society, but ultimately, humans created it to answer the questions that at one time could NOT be answered. Which over time have been slowly answered. Leaving the one question still debated by many "Why are we here?" Which this debate is now totally dependent on ones position. Creationists argue, we are here because of god. Scientists argue we are here because the universe moves towards constructs of higher orders of complexity and we are here to further that complexity. To seek out the meaning to life, the universe, and everything.
42 BTW.
