Lee Irons delivered an excellent lecture at the Bahnsen Conference on Kline’s covenantal structure and how it relates to the question of culture and common society. The three categories of Adamic Covenant of Works, Noahic Covenant of common preservation (which I prefer to “common grace” because that is a loaded term full of ideas I don’t agree with), and Christ’s Covenant of Grace help frame our understanding of life in this world and the world to come. Definitely give it a listen.
The point that must be stressed is that affirming this covenantal structure does not in any way necessitate Van Drunen’s incoherent dual epistemology. His division between natural and special revelation, claiming that only natural revelation has relevance to the common realm under the Noahic Covenant, is unbiblical. I agree with Bahnsen that such an appeal does not make any sense because 1) anything revealed in general revelation is also revealed in Scripture, and 2) anything revealed in general revelation is clouded and obscured by sin. Thus arguing we should look only to natural revelation in determining civil ethics is to argue we should take off glasses that allow us to see properly and instead grope around in the dark with poor, blurred vision trying to discern the same truth we can see clearly with our glasses on (Calvin’s analogy).
But when we put those glasses on and look to Scripture to answer the question of civil ethics, we do not see any warrant for a modern society built upon a Mosaic model. Rather, we see that all nations today remain under the Noahic Covenant, while the typological Mosaic Covenant is obsolete.
God himself set human culture apart as a common realm for both the elect and the non-elect as the backdrop for the unfolding of his plan of redemption in Christ. And that’s why Kline emphasizes this important point – that it was established by a formal covenant in Genesis 9.
So I think Kline would take the Van Tillian “no neutrality” objection and he would turn it on its head. As a good Van Tillian, Kline would insist that we must submit our autonomous thought to God’s sovereign authority as revealed in Scripture. God himself reveals, in Genesis 9, that God himself has established this temporary, legitimate, but non-holy common grace cultural realm. And so we must submit our thinking to God’s covenant word. @48:00
In seeking to understand civil ethics under the Noahic Covenant, then, we do not look to natural law apart from Scripture. Instead, we look to discern what the Noahic Covenant commands. Because the Mosaic Covenant, though obsolete, contains the most explicit revelation of God’s law and many other things, we can look to the Mosaic law to learn about the transcovenantal moral law (10 commandments) that exists apart from Mosaic law. We can also look to the Mosaic law to see further development of Noahic law. For example, seeing how Mosaic law handles Gen 9:6 (Ex 21:23, Deut 19:21, Lev 24:20) gives us insight into the implications of Gen 9:6 for today.
Two sermons from Samuel Renihan also do a good job of setting up this framework under the Noahic Covenant.