Homo Sapiens evolved so much because of language. They were the first species to communicate about abstract things.
Equality is important today and world is moving towards social equality, racial and caste discrimination is slowly going away. But what about economic equality? Like caste and race, money is also an imaginary entity. Still we do have sections like rich, middle class and poor, and no one seems to have a problem with it.
The ability to speak about fictions is the most unique feature of the Sapiens language.
None of these things exists outside the stories that people invent and tell one another. There are no gods in the universe, no nations, no money, no human rights, no laws and no justice outside the common imagination of human beings.
As time went by, the imagined reality became more powerful, so that today the very survival of rivers, trees and lions depends on the grace of imagined entities such as United States or Google.
One of the history's few iron laws is that luxuries tend to become necessities and to spawn new obligations. Once people get used to a certain luxury, they take it for granted. Then they begin to count on it. Finally, they reach a point where they can't live without it.
To say that a social order is maintained by military force immediately raises this question: what maintains the military order? It is important to organize an army solely by coercion. At least some of the commanders and soldiers must truly believe in something, be it God, honour, motherland, manhood or money.
Money is more open minded than language, state laws, cultural codes, religious beliefs and social habits. Money is the only trust system created by humans that can bridge almost any cultural gap and that does not discriminate on the basis of religion, gender, race, age or sexual orientation.