What is the most important requirement for a body, a group, a team, a family, a nation, or a machine to function at its highest potential? Unity.
In order for progress to occur, when there are parts that rely on one another it is of the utmost importance those parts must work in unison with one another.
The “parts” of the society are the people. Progress can only be achieved, when the people of that community live in harmony with one another.