Right polity properly situates a Christian under the rule of Christ during the time of his or her discipleship in this world. Wrong polity either wrongly imposes human rule where Christ does not mean for it to be, or it evacuates his rule from a certain area of the Christian’s lie where it should be.
Right polity hems us in and keeps us from our excesses while also providing a platform for growth and ministry and freedom. Wrong polity erases the lines we should not cross while undermining those platforms that God intends for us to stand on and blocking the paths where we hope to walk.
Right polity protects the gospel from one generation to the next. It is the platinum prongs that hold the diamond of the gospel in place. Wrong polity loosens those prongs so that the diamond of the gospel eventually falls to the ground and gets lost. It leaves heresies and hypocrites unchecked. It lets hurting sheep wander off and fall into canyons.
Right polity protects the path of life. Wrong polity, over time, helps to lay the path for authoritarianism and moralism in one direction and nominalism, liberalism, and atheism in another.