Little myths come and go, but a great one, can last for thousands of years. People are still captivated by ancient myths like the Epic of Gilgamesh, Isis and Osiris, and the Popol Vuh. Of course, Christianity isn't even considered a myth (yet), by the masses that follow the religion 'fundamentally' (imo an akward term for taking the metaphor literally).
It seems, the epic myths aren't created in the same manner, as the little myths and stories, like the Star Wars saga, The Lord of the Rings, The Chronicles of Narnia etc., which are all created by a single individual, familiar with symbols and archetypes.
Epic myths like the birth and life story of the Buddha, as told in the Pali Canon, or the birth/life/death and resurrection of Christ, or those listed above, seem quite different; they seem to be created naturally, over the course of time by a number of different people. They may begin with the vision of a single 'spiritual hero', but their experience is built upon later, appearantly by people attempting to show their prowess, concerning knowledge of psychological death and rebirth, the different degrees of the mystics transcendent experience, and the symbols and archetypes that represent it.
Without the primary vision, i.e., the psychological death and resurrection of the spiritual hero, and an acccount of their transcendent experience--and without the wise men, intimately familiar with the symbols and archetypes that represent the experience--you have no epic myths, just epic stories and little myths...
Something to keep in mind: all the names and forms, for God, in all his names and forms, come from some form of human.