What role did the environment and religion play in the evolution of Egyptian civilization?

To understand ancient Egypt, one must consider the paramount significance of its environment and religion.
The most important environmental factor in the history of ancient Egypt was the Nile River. The Nile River provided transportation. Moreover, it was crucial to its agricultural and economic systems. The Nile River's annual flooding provided fertile ground for Egyptian farmers. It was the uniting feature of the country's geography, too. Only land adjacent to the Nile was fit for human habitation: the rest of the vast nation was too torrid. For the ancient Egyptians, the Nile was the center of the universe.
Ancient Egypt was governed by pharaohs who were thought of as living gods. The pharaoh personified the nation. Pharaoh literally means "great household," and the office of the pharaoh was central to political stability in Egypt. This stability and longevity endured for millennia. The great pyramids were built as monuments to the pharaohs. The belief in the pharaohs' divinity served as a glue that bound the nation together. Also, because of this belief, the Egyptians regarded themselves as superior to foreign civilizations. Osiris and Isis, two of the main gods, were especially significant. Osiris was seen as the first pharaoh, and subsequent pharaohs were descended from him. Dead pharaohs were mummified to prepare them for the afterlife.