So how does Christ now rule the many institutions and communities of this world other than the church? The answer is that He rules them through the Noahic covenant, for they are institutions and communities of the common kingdom. They operate according to the same basic principles and purposes as before Christ’s first coming. What is different is that God now rules them through the incarnate Lord Jesus, the last Adam who has entered into the glory of the world-to-come.
VanDrunen, Living in God’s Two Kingdoms p. 118