Parshat Shemot devotes a great deal of emphasis on trying to understand Hashem's nature. There apparently was a seven day dialogue between Hashem and Moshe Rabbeinu mainly convincing Moshe that he was the right man for the job to lead the Jewish people out of Egypt.
Moshe asks a number of questions as to how he he is to teach the people about the Master of the Universe. When Hashem answers אהיה אשר אהיה, that is generally understood to mean that G-d will always be with us through every difficulty that we might encounter. It also was made abundantly clear that it was impossible for man to truly comprehend Hashem's true essence.
All of this was meant to reinforce the total awe that we are supposed to have towards G-d. We were to also realize our total dependence on Him. This is a prerequisite in establishing the foundations of our religion that is based on the dictates of Hashem Himself.