It's really very simple. Have a purpose as a nation and work towards it.
Our purpose as a country is made implicit in the constitution:
We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.
However, the constitution itself has become more and more
marginalized lately, by the men
who swore to uphold it.