Oscar Cullman, The State in the N.T., pp. 90-91.
The church's task with regard to the state which is posed for all time is thus clear. First, it must loyally give the state everything necessary to its existence. It has to oppose anarchy and all zealotism within its own ranks. Second, it has to fulfill the office of watchmen over the state. That means it must remain in principle critical towards every state and be ready to warn it against transgression of its legitimate limits. Third, it must deny to the state which exceeds it limits, whatever such a state demands that lies within the province of religio-ideological excess; and in its preaching, the church must courageously describe this excess as opposition to God.