I think the problem between us is one of semantics, that is we need to clarify concepts and premises underlying our claims. There is a certain "literal" interpretation of the Bible which looks at what the text says on its face and cites verses and chapters of scripture as specific prooftexts. The specific/literal approach, one many evangelicals are fond of following. In that sense, the Bible does not speak to unalienable rights, political or religious liberty. I've read the parts that supposedly do from cover to cover. It's an open and shut case. I'm hesitant to argue the issue further with the good King, because he can be, what Gary North has termed a "tar baby" when someone disagrees with him on an issue about which he is passionate.
After reading every single word that he and Gregg Frazer wrote on Romans 13 and rebellion this passage from North's article comes to mind:
Now, he expects you to refute him. No, he demands that you refute him. Can you refute him to his satisfaction? It would have been easier for the Pope to have persuaded Luther that he had it all wrong.
Now, if one takes a DIFFERENT interpretive approach on the Bible, I suppose you can get the concept of unalienable rights to political liberty and otherwise. It's where you take a general principle from the text -- indeed it then helps to supplement that general principle with natural law as discovered by man's reason -- and then draw specific conclusions therefrom.
In King's case it's the general principle that all humans are created in the image of God (Imago Dei) and therefore, possess inherent dignity. Note that general idea says nothing in the specific sense of unalienable rights, a right to worship freely, a right to be free from chattel slavery. But take that principle, throw in a some Aristotelian natural law as discovered by reason as a supplement. Come to your conclusions and then use that as an interpretive premise to overcome all of the many verses and chapters of the Bible which suggest that men in fact do not have a "right" to worship freely and to be free from chattel slavery and viola you have your preferred outcomes.
Me, I'm going to keep on stating the Bible does not teach the concept of unalienable rights, to political or religious liberty. And I think, at the very least, conservative evangelicals should agree with me.