In his commentary on the Heidelberg Catechism, Ursinus takes time to discuss the Law’s Threefold Division. In doing so, he also addresses those that would advocate that the Mosaic Law’s civil code must be the rule of all modern nations (read: “theonomy”). A third objection he answers is somewhat prevalent in today’s Theonomy movement (pp. 494-95).
Here is the objection:
The best and most wholesome form of government is always to be retained. The form of government established among the Jews was the best and most wholesome, for the reason that it was instituted by God. Therefore it is to be maintained.
Here is Ursinus’ answer:
There is here a fallacy in taking that to be absolutely true, which is true only in a certain respect. The form of government established among the Jews was the best, not absolutely, but only for that time, that country and nation: for there were many things in it adapted to the state and condition of that nation, country, time, and ceremonial worship, the observance of which would now neither be proper nor profitable, because the causes on account of which those laws were given to the Jews are now changed or removed; as giving a writing or bill of divorcement, marrying the widow of one’s kindred, etc. God did not, for this reason, institute this form of government that all nations and ages might be bound by it; but only that his own people might, by this discipline, be separated for a time from the surrounding nations.
If any one should object and say, that if Christians are permitted to observe and conform to the laws of other nations, such as the Greeks or Romans, etc., much more ought we to observe those that were given by Moses, the servant of God; we readily grant the argument, if this observance is rendered without attaching to it the idea of necessity; or if these laws are observed, not because Moses commanded and enjoined them upon the Jewish nation, but because there are good reasons why we should now comply with them; and if these reasons should be changed, to retain the liberty of changing these enactments by public authority.
Before proceeding through the Decalogue in his exposition of the Heidelberg’s Gratitude section, Ursinus thought it was necessary to articulate the Law’s Threefold Division in order to ensure that people understood why he and the Heidelberg only addressed moral law. In other words, he and Olevianus consciously kept the Old Covenant civil and ceremonial law out of the Heidelberg. Directly observing them are not part of the Christian’s life of Gratitude.