One of the other themes of the Twenty-Seven Propositions describing two-kingdom theology is the notion that the Bible is binding on all people:
7. Scripture is not given as a common moral standard that provides ethical imperatives to all people regardless of their religious standing.
The Reformed confessions testify that the moral imperatives of Scripture are binding on all men everywhere.
This does make the world safe for theonomy and for theocracy, since another common assertion of 2k critics is that special revelation must interpret general revelation, which implies that only those whose souls have been regenerated by the Holy Spirit may interpret general revelation, because only those with the eyes of faith can interpret Scripture aright, the necessary lens for interpreting the light of nature.
Aside from the covenantal implications of Scripture which make havoc of this critique of 2k, Scripture itself confounds this criticism. For if Paul were writing to the Corinthians with this anti-2k outlook, he could never write the following:
When one of you has a grievance against another, does he dare go to law before the unrighteous instead of the saints? Or do you not know that the saints will judge the world? And if the world is to be judged by you, are you incompetent to try trivial cases? Do you not know that we are to judge angels? How much more, then, matters pertaining to this life! So if you have such cases, why do you lay them before those who have no standing in the church? I say this to your shame. Can it be that there is no one among you wise enough to settle a dispute between the brothers, but brother goes to law against brother, and that before unbelievers? To have lawsuits at all with one another is already a defeat for you. Why not rather suffer wrong? Why not rather be defrauded? But you yourselves wrong and defraud—even your own brothers! Or do you not know that the unrighteous will not inherit the kingdom of God? (1 Corinthians 6:1-9 ESV)
Notice that this is an imperative that according to the anti-2k outlook applies to all people (even though Paul is writing directly to the saints at Corinth). If Paul believed that Scripture was given for believers and unbelievers alike, then his admonition here would be to tell unbelievers to take their cases to ecclesiastical courts. And if unbelievers take their cases to those who rule outside the church, they are guilty of sinning. Talk about being damned if you do and damned if you don’t.
But Calvin doesn’t fall for this folly.
. . . if any one has a controversy with a brother, it ought to be decided before godly judges, and that it ought not to be before those that are ungodly. If the reason is asked, I have already said, that it is because disgrace is brought upon the gospel, and the name of Christ is held up as it were to the scoffings of the ungodly. For the ungodly, at the instigation of Satan, are always eagerly on the watch for opportunities of finding occasion of calumny against the doctrine of godliness. Now believers, when they make them parties in their disputes, seem as though they did on set purpose furnish them with a handle for reviling. A second reason may be added — that we treat our brethren disdainfully, when we of our own accord subject them to the decisions of unbelievers.
In other words, Calvin, who ministered in a town very much unlike Corinth, where the rulers of Geneva were members of the church, still recognizes that these words Paul apply to Genevan Christians, that is, that they should not look for justice with fellow Christians but should bear each other’s burdens patiently and endure slights and offenses.
I acknowledge, then, that a Christian man is altogether prohibited from revenge, so that he must not exercise it, either by himself, or by means of the magistrate, nor even desire it. If, therefore, a Christian man wishes to prosecute his rights at law, so as not to offend God, he must, above all things, take heed that he does not bring into court any desire of revenge, any corrupt affection of the mind, or anger, or, in fine, any other poison. In this matter love will be the best regulator.
This is moral instruction, in other words, that applies to Christians not to unbelievers. Christians are capable, by the work of the Spirit, of not seeking revenge. Paul concedes that unbelievers are not.
What is also interesting to observe is that Calvin does not believe that Paul is invalidating the rule of ungodly magistrates, as if it were wrong to take certain civil matters to the courts, or as if the ungodliness of rulers invalidates their rule:
Paul does not here condemn those who from necessity have a cause before unbelieving judges, as when a person is summoned to a court; but those who, of their own accord, bring their brethren into this situation, and harass them, as it were, through means of unbelievers, while it is in their power to employ another remedy. It is wrong, therefore, to institute of one’s own accord a law-suit against brethren before unbelieving judges. If, on the other hand, you are summoned to a court, there is no harm in appearing there and maintaining your cause.
Calvin also goes on to distinguish in ways that would send neo-Calvinists, in the worlds of Ralph Kramden, “bang, zoom, to the moon” between the public matters before magistrates and private matters of Christians.
We must always keep in view what causes he is treating of; for public trials are beyond our province, and ought not to be transferred to our disposal; but as to private matters it is allowable to determine without the cognizance of the magistrate. As, then, we do not detract in any degree from the authority of the magistrate by having recourse to arbitration, it is not without good reason that the Apostle enjoins it upon Christians to refrain from resorting to profane, that is, unbelieving judges.
So if anti-2kers want to argue that biblical morality applies to all human beings, they may want to take up their case with the apostle Paul. Or they could reconceive their claims with the same scrupulosity they apply to 2k advocates.