Do you buy this? http://www.touregypt.net/featurestories/pyramidreligion.htm Here's a sample:
We see Egypt's ancient pyramids as monumental structures that inspire our imagination with awe and wonder. They were monumental tombs for the kings. but why did they Egyptians go to so much trouble, toiling sometimes over many years in order to build them? In fact, while tombs indeed, the great pyramids were also fundamental to their religious beliefs.
A part of ancient Egyptian life was the Nile inundation. As rains fell during the spring in the Ethiopian highlands the level of the Nile River in Egypt rose above its banks, flooding the Nile Valley between June and October. This turned much of the valley into large lakes, but as the waters receded, they left behind fertile silt from which new life would immerge, at first on the highest mounds of earth.
It was almost certainly this annual experience that the Egyptians linked to their concept of creation. One of their earliest creation myths envisioned the first place in the world as a mound of earth emerging from the waters of a universal ocean. Here the first life form was seen as a lily, growing on the peak of the primeval mound. To the Egyptians, the lily was connected with a god named Nefertum, who's name means "perfect and complete". Nefertum was honored as The Ruined pyramid of Snefru standing at Meidum seems to rise above a primeval seaa harbinger of the sun, which rose from the lily's petals to bring life to the newly created world. Even the mound itself was deified as a god named Tatjenen, meaning "the emerging land".
It seems that the earliest temples of Egypt, particularly in the north, sometimes incorporated a mound of earth as a symbol of the original site of all life. The earliest such mounds may have been a small hill of earth or sand, but the icon eventually took the form of a small pyramid carved from a single block of stone, known as a bnbn (benben). This name comes from the root, bn, which means to "sell up" or "swell forth". The benben also, because of the sun's part in creation, came to be an icon of both the primeval mound as well as the sun which rose from it. In fact, the Egyptian word for the rising sun is wbn, which comes from the same root as benben.
Thus, from the outset, the pyramid shape represented the idea of new life, emerging from a mound of earth to be bathed in the light and warmth of the sun. However, to the ancient Egyptians, the benben was more than just an image. Like the primeval mound itself, the Egyptians thought that it somehow incorporated the very power of life itself and even the force that made it possible for new life to emerge after a period of dormancy.