The brilliant American psychologist Julian Jaynes (1920-1997) published a fascinating book with a rather intimidating title: The Origin of Consciousness in the Breakdown of the Bicameral Mind (c. 1976).
According to Jaynes, ancient people in the bicameral state of mind would have experienced the world in a manner that has some similarities to that of a schizophrenic. Rather than making conscious evaluations in novel or unexpected situations, the person would hallucinate a voice or "god" giving admonitory advice or commands and obey without question: one would not be at all conscious of one's own thought processes per se. Research into "command hallucinations" that often direct the behavior of those labeled schizophrenic, as well as other voice hearers, supports Jaynes's predictions. (Wikipedia)
People of Homer’s time did not “think” the way we do. They actually saw and communicated with the various gods and goddesses who appear in ancient literature. When a person had a problem, according to Jaynes, he did not necessarily try to think it out but was more likely to pray for an answer from one of the gods or goddesses who resided in one of the two separate halves of his own brain. One of the examples Jaynes offers is the scene in Homer's Iliad in which Achilles prays to his mother, who is a minor goddess, for advice and assistance after his friend Patrocles is killed and his armor is stolen.
Jaynes studied world literatures in depth. He is an excellent writer, partly because of his exposure to so many great ancient and modern writers. His book provides a plausible answer to the question, “In Homer's Odyssey, why do mortals need help from the gods?"
The term "bicameral mind" means that before the origin of conscious the two halves of the human brain were independent of each other. Communication from one "brain" to the other came in the form of visions or hallucinations. The ancient Greeks believed in their gods and goddesses because they believed they saw them and spoke to them regularly, although these gods and goddesses actually only existed in their own minds.