From American Vision:
Once or twice a year or so, someone asks me about something a critic says about “Theonomy,” usually because they have encountered some straw man version of it. They are now confused and want clarification. “So and so has said this. . . .” “Have you seen this link? . . .” Such occasions are good for helping the honest inquirer and exposing the misinformed and the dishonest all at the same time.
In order to clear any confusion, here’s both a reiteration of a simple definition of Theonomy that no theonomist would disagree with, and the proof that this simple perspective has always been the same, and always will be.
The word “Theonomy” comes from two Greek words, theos (God) and nomos (law). Together, these words simply mean “God’s law.” Since every Christian has some view of the role of God’s standards for living, every Christian believes in “theonomy” to some degree. What has come to be called “Theonomy,” however, is a particular view of the role of God’s law that includes the application of aspects of Old Testament law to all of life including the social realm and civil government. Those who hold to this view are properly called “theonomists.” . . .
Theonomy, then, can be defined as follows: the biblical teaching that Mosaic Law contains perpetual moral standards for living, including some judicial laws, which remain obligatory for today.
“Theonomy” is a much broader subject than merely civil government and social theory, but this is where it is, in my opinion, most distinct from other positions. It is also where it has been most controversial, owing to the fact that most Christians in history have allowed the civil realm to be governed by pagan and humanistic ideas and laws. Biblical direction here has always been badly needed.
Basically: God demand justice and righteousness, privately and publicly. And it is in the Law that God handed to Moses — and modified/fulfilled by Jesus Christ — that defines these standards.
If you don’t care to be spat upon by your secularist betters, you had better uphold – and enforce – God’s standards. In private, and then in public.