Famous Anabaptist
Blessed is the people that know the joyful sound: they shall walk, O LORD, in the light of thy countenance. Psalm 89:15
And
Blessed is the nation whose God is the LORD, the people He has chosen as His inheritance! Psalm 33:12
Yes, we understand that the Church is uniquely “God’s people” but that in no way suggests that a people as a people could not swears oaths of fealty unto God so as to make it clear that they take Him for God and will submit to him as His people.
Consider here that when Clark “reasons” like this he is reasoning like a Dispensationalist and indeed one might even say that Clark is reasoning like a Marcionite. The God of the OT. per Clark, is a different God from the NT. In the OT, per Clark, God had one set of ethical standards for His people but in the NT God has given up with a revealed law for his people and has now punted to a thing called Natural law. Naturally this is what makes the new and better covenant new and better (sarcasm off).
Ursinus in his Commentary on Heidelberg (p. 506) writes,
“Furthermore, although natural demonstrations teach nothing concerning God that is false, yet men, without the knowledge of God’s word, obtain nothing from them except false notions and conceptions of God; both because these demonstrations do not contain as much as is delivered in his word, and also because even those things which may be understood naturally, men, nevertheless, on account of innate corruption and blindness, receive and interpret falsely, and so corrupt it in various ways.”
Zacharias Ursinus
Clearly Ursinus did not agree with Clark on the power of Natural Law as a standard for a social order.
Finally, as all men are theocrats even if they are so stupid that they can’t realize that Clark himself is doing all kinds of line blurring along with everyone else.