Francis Roberts is an unfortunately unknown 17th century Reformed theologian.  Thankfully, Won Taek Lim has published a helpful survey of his covenant theology which should help give him the attention he deserves.  See details about his book here.  Roberts work is really the definitive treatment and defense of the Reformed consensus on the doctrine of the covenant. 

 

I plan to transcribe this entire section to make it available in digital format,  but as you can see it will take quite awhile.  Until then, I have attached the pages in which he deals with the Mosaic covenant below. 

 

Roberts deals with the four views propounded among various theologians during this period: (1) that the Mosaic covenant was a covenant of works, (2) that it was a mixed covenant, (3) that it was a subservient covenant, (4) that it was a covenant of grace.  The first position was that taken by mainstream Lutheranism (as Roberts notes).  The second position is a very idiosyncratic position taken by only a few Reformed writers.  The third position was that of the Amyraldians (rejected by both the WCF 7:6, as well as the Formula Consensus Helvetica in Switzerland).  The final position was that of the confessional consensus of orthodox Calvinism. 

 

The reader should especially note in which Roberts coordinates the view taken by a small minority of Reformed theologians (that the Mosaic covenant was a covenant of works) with the Lutheran theologians, especially represented by Johann Gerhard (cf. 739-40).  We cannot properly understand the distinctly Reformed doctrine of the Mosaic covenant unless we understand it in its 17th century polemical context!  Some Reformed writers took a "Lutheran" position - and they did not go uncriticized for it. 

 

In our opinion, this is the best and most detailed treatment of the issue in the 17th century.  If you really read only one thing on the Mosaic covenant, read this!  I don't think you can put it better than Roberts does!  His treatment is polemical, theological, exegetical, and pastoral all at once. 

 

In my opinion, it should be a high priority for the Reformed Churches to see that this important work gets reprinted soon.