Since Calvinism (with its Augustinian roots, and Augustine was the great justifier of the marriage between the church and state) is a belief system within the stream of Christendom, it falls within these same critiques. (redeeminggod.com)
Thus Catholicism was the great justifier first of feudal society, then of monarchy; and today, in exactly the same fashion, it justifies revolution. (religion-online.org)