Plato teaches that the arche and telos of politics is liturgical action. No 'purely secular' foundation of a polis is possible. Politics necessarily opens beyond itself and is therefore subject to theological critique and theotic fulfillment (or not). The Republic teaches about the primacy of the liturgical; in the Laws Plato presents the proper liturgical act for human beings.
Fendt, Gene, "Philosophy as Liturgical Action: An Essay on Plato's Politics" (2001). The Society for Ancient Greek Philosophy Newsletter. 391.