In the Epic of Gilgamesh called Enkidu's Dream written around 2000 BC, the bleak concept of death being an express outcome of sins committed in life, there is a very apt reference to kings' "crowns put away forever" and the ones who stood at any worldly position on Earth "stood now like servants". This depicts how the Mesopotamian had an acute belief that the afterlife was merely suffering and distress to say the least and the dead were both pitied and feared.
Furthermore, the references to "vampire foot", "lion's foot" and "eagle's talon" all illustrate the fears that the people of this time had and how they associates all that they feared with the dismal possibility of death and what they figured would happen afterwards.
Contrary to this dreary outlook to life after death of the Mesopotamian people, the Greeks were more optimistic about the afterlife. Although they believed that the people who did wrong on Earth will be punished severely by the gods in the afterlife, they also believed that the good doers will have an eternally peaceful life; modern researchers believe that the concept of heaven and hell originated from this era.
The Myth of ER which is the concluding part of Plato's dialogue called The Republic, talk ...