Prometheus is best known for his theft of fire from the gods. His name literally means, "Forethinker." By obtaining fire for humanity, he enabled humankind to emerge from a slumbering unconsciousness that had lasted eons. The theft of fire is directly connected with the human Ego, for by Prometheus' gift of fire, humankind began the journey toward developing Ego and widening its powers. I see in this myth the warring of two modes of being: 1) the unconsciousness that Zeus desires to perpetuate; and 2) the consciousness of a strong and powerful Ego that would take humanity to the very threshold of the most perplexing questions in existence.
If we look more deeply into the story, we find that everything bestowed by Prometheus on mankind is connected with the human Ego, while Zeus is portrayed as a divine power which inspires and ensouls men in whom the Ego has not yet come to full expression. If we look back over the evolution of the earth, we find in the far past a humanity in which the Ego was no more than an obscurely brooding presence. It had to acquire certain definite faculties with which to educate itself. The gifts that Zeus could bestow were not adapted to furthering the progress of mankind. In respect of the astral body, and of everything in man apart from his Ego, Zeus is the giver. Because Zeus was not capable of promoting the development of the Ego, he resolved to wipe out mankind. All the gifts brought by Prometheus, on the other hand, enabled the Ego to educate itself. Such is the deeper meaning of the legend (Rudolf Steiner, Metaporphoses of the Soul One: Lecture 2: The Mission of Anger).
Prometheus Carrying Fire, by Jan Cossiers
The myth of Prometheus is analogous to the story of Adam and Eve's expulsion from the Garden of Eden. Both stories tell of the birth of human consciousness. Adam and Eve came to a knowledge of good and evil, while, in the Greek myth, humanity was bestowed the gift of knowledge of ourselves and the world. Both Prometheus and Adam/Eve were severely punished for seeking more knowledge. Prometheus, being immortal, was bound to a rock, where Zeus' eagle would come everyday to consume his daily regenerating liver.
Why did the gods think the birth of consciousness was something that required such dire consequences? Perhaps they did not want us to become as gods ourselves, possessing conscious awareness of the Universe. Perhaps they foresaw the dangers of unleashing the fire of Ego, with its concomitant ability to destroy the very world in which they had placed us.
Remember, this is a myth, not literal history. This is a story of the human Soul and how it has developed through the ages. The same fiery Ego that created nuclear weapons is the reason why I must remind you of this. In our ego-driven quest for knowledge, we sometimes forget how dangerous the overinflated Ego can be.
Prometheus is traditionally seen as a great benefactor of humanity. He is known as the original source of technology and the useful arts. I think his theft of fire is more beneficial as the catalyst that sparked our thirst for self-knowledge.