The concept of a god has been around, for mankind, as long as man has been conscious of himself as separate from other creatures - having consciousness. The concept of god came into being in response to anything more powerful than the self, a common reaction throughout the Universe. At first, this takes the form of animism, where wind, thunder, and savage beasts are gods. As when dealing with other tribal members or even some wild beasts, the newly conscious prehistoric man understood, through experience, that some of his gods could be placated. Hand over the food, and all is well, for instance. Placating angry tribal members often involved sacrificing a friend to save oneself. For instance, if the question of who stole the food comes up, if one young individual meets the blind rage of the angry elder, then the others are off the hook. The concept of the scapegoat is born.
In time these concepts become sophisticated, with sacrifices ritualized and the concept of the god expanded upon to include motive and rules. This expansion was not the common man's doing, but sly religious elites who desired an easy parasitic living. They became the keepers of the rules, and performed the ritual sacrifices. As keepers of the rules, the rules understandably began to twist in the favor of the religious elite. Organized religion was born. At some point in the intellectual and spiritual development of mankind, some began to see these flaws in organized religion and think for themselves. But casting away the rigidities of organized religion did not entirely satisfy, as these individuals sensed that something else was going on. Intuitively aware of the eternal soul within them, they sensed that the separation of body and soul was possible, and that reincarnation existed. In contact with spirits in higher dimensions, they became intuitively aware of the spiritual realm.
That's where we are today, with mankind. No answers, just intuitive understanding and a lot of organized religion conducting their rituals and laying down rules. Mankind, in increasing numbers, is coming into contact with extraterrestrials who have an understanding of the larger picture. At last, they will have an answer. Unfortunately for the anxious, this is not to be the case, for we, also, do not have the answer. Our understanding of how the Universe works is greater than yours, but what started it all and why are still outstanding questions in the Zeta minds. Sorry about that. We too must progress to higher densities of spiritual maturity before we can gain a greater understanding.