Both cultures also had priests and priestesses for their gods, which acted as leaders and used ceremonies to appease the gods they represented. Their religions also had a heavy influence on both cultures governments.
The Egyptians and Mesopotamians had very different opinions on the afterlife, however; for the Egyptians, so long as you aggravated no gods or committed horrible acts, there was a peaceful paradise waiting for you in death. For the Mesopotamians, it was much more grim -- your afterlife would be a continuation of your life on Earth. If you were born a king, you would be one in the afterlife. If you were born a peasant, you were stuck as one even in death. Additionally, the food would be awful, and if your dead relatives didn't take care of you, you were doomed to a very unpleasant existence.
Both Mesopotamian and Egyptian religions were polytheistic, and both anthropomorphized their gods.
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