The central idea of the purpose of human existence is the creation of consciousness. Our purpose, I think is to bring light into the darkness of being, to increase consciousness by becoming aware of what is hidden in the unconscious.
Carl Jung developed a new myth for modern man, one based around the idea that man is indispensable for the completion of creation. Existence is only real when it is conscious to someone and this, he argues, is why the divine needs conscious men – whoever knows the divine has a moderating and loving effect upon it. Once the union of opposites is attained, man and the divine are reconciled. In psychological terms, the Ego and Soul are finally aligned, an the creation of higher consciousness changes not only the individual but the nature of creation itself.