After all, this was Paul's position in Romans 13:
"8 Owe no one anything, except to love each other, for the one who loves another has fulfilled the law. 9 For the commandments, “You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet,” and any other commandment, are summed up in this word: “You shall love your neighbour as yourself.” 10 Love does no wrong to a neighbour; therefore love is the fulfilling of the law."
Paul observed, in the context of discussing the State enforcing laws, that these laws should be guided by the laws of God. He explicitly quotes the second tablet of the Mosaic Ten Commandments, and then notes that applying all the laws pertaining to the treatment of neighbours fulfils the principle of love. This is a "Christian Nationalist" approach if I ever saw one. Paul's argument is governments are God's servants and should rule like they are, for the righteous good of people.
The Baptist historical position is that the laws pertaining to loving your neighbour should still be enforced, and the ritualistic and priestly laws (the priesthood, food laws, etc) no longer apply, because they are fulfilled in Christ. All versions of Christian countries apply either a similar approach, to varying degrees of this, or draw even more heavily on the wider Old Testament laws.
Many of the more egregious beliefs of false religions can be curtailed by an application of the second tablet of the law. They can also be curtailed by limiting who can live in your society, which really is an extension of loving your neighbour.
I think Locke's approach in Letter Concerning Toleration
is the best, and led to the most free societies ever, the modern English-descended nations. These post Reformation English speaking societies achieved a balance between liberty and godly societies, at least for a time, until we ignored Locke's warnings.
Locke warned in Letter Concerning Toleration about the dangers of strangers, especially from vastly different religious cultures, being allowed to live in your society. Ergo there is wisdom in banning or heavily limiting immigration, and placing limits on foreign trade, because international trade promotes immigration. By limiting these things you reduce the influence of foreign ideas and false religions in your society, and you prevent the quick the corruption of your law codes.
Machiavelli notes that the freest nation in all of Europe in the 14th and 15th centuries was Germany because it neither permitted immigration in any meaningful numbers, nor did it allow much free trade from outside of Germany. They traded liberally within, which preserved their culture and identity and their liberty. Once you permit both these things, immigration and international free trade, your laws will be corrupted because it encourages your society to tolerate things your laws were never intended to tolerate, because you will have people in your society who live in ways your laws did not envision. Locke makes a similar argument in the 17th century work Letter Concerning Toleration.
So Christian Nationalism, with varying degrees of application of Old Testament principles, is both biblically and historically the best approach - as observed by some of the greatest thinkers in history (and Paul's own writings support this).