Finding the real meaning of any work of art is a notoriously difficult thing, and it certainly not easy with a game like Civilization which isn't overt about it's messages instead it relies upon allowing its mechanics to resonate with its players and allow its meaning as Thomas Jefferson might have put it 225 years earlier 'self evident'. The concept of self-evident truth is universal, but in all its forms & variations it remains incredibly elusive next to impossible to reproduce, rationally de-construct or describe, but its something that games have always been very good at.
This is Civ's implicit promise to the gamer, 'play me' it says 'and it will all become clear' 'this is how the world works' 'this is how a civilisation must be'. A player is expected to gradually come to see this truth, and that anyone who does not understand and accept it is fated to fail, for their civilisation will not 'stand the test of time'. Its a message that is driven home every step of the way as a player advances into the future.
All men are created equal