There is a divinely established social order.  There may not be a divinely ordered human government but there is a divinely ordered social structure ungirding it.  The Old Testament explains what it is and it is not only for the Jews but for the whole world.  That order was based on justice, mercy and humility.

This is from Prof Laetsch –

Here is a lesson for every Christian pastor and layman. It is the duty of every true Christian, and particularly of every Christian pastor, to call the congregation’s attention to maladjustments of the social order within its midst wherever they are in conflict with the Word of God, and not only with human conception of an ideal social order. Christians must be told that, in permitting such conditions to exist without as much as a word of protest, they are sinning against the clear word of God, applicable to all times and circumstances, “Hate the evil and love the good,” Amos 5: 15. Above all, the Christians themselves in their social relations are not to become or remain guilty of any transgression of God’s Holy Law. The sinfulness of such perversions of their social duties must be clearly pointed out to them. They must be threatened with the wrath and punishment of God. They must be told that persistence in such sins excludes them from the Kingdom and will lead to their excommunication from the Christian congregation, because they are reversing the will and word of God, they are loving the evil and hating the good.