(This is a repost from May, 2012)
What exactly is the Mosaic/Sinaitic covenant? Is it part of the covenant of grace God established with his people beginning with Genesis 3:15? Or is it part of the covenant of works God made with Adam before the fall? Both? Neither? In the history of Reformed theology, good theologians have answered these question differently. Michael Brown, in Christ and the Condition: The Covenant Theology of Samuel Petto, provides a snapshot of a few different older Reformed theologians and their positions on this issue. Here’s a short sample (note: I’ve summarized Brown’s descriptions).
Zacharias Ursinus: Ursinus taught that there was one covenant of grace in the history of salvation. Since the fall, he said, salvation is by grace alone, through faith alone, because of the Mediator, Christ alone. Ursinus also said that while the substance of the covenant of grace is evident in the Mosaic covenant, it also teaches what the law demands: perfect obedience. In other words, Ursinus believed that the Mosaic covenant was part of the covenant of grace, but it also displays a law/gospel distinction which is similar to a covenant of works/covenant of grace distinction.
William Perkins also made the law/gospel distinction evident as he discussed the Mosaic covenant. The Mosaic covenant had a pedagogical function that drove the people to the covenant of grace (the gospel). He also taught that the Ten Commandments were a reflection of the pre-fall covenant of works.
Though not as well-known as other Reformed theologians, Amandus Polanus was a leading German Reformed figure around the turn of the 17th century. He too taught a distinction between the covenant of works and covenant of grace. He said that Sinai was a repetition of the covenant of works. The Sinaitic covenant was given to “thrust us forward to seek to be restored in the covenant of grace.”
William Ames described the Sianitic covenant in terms of substance and accidents. In other words, the substance (essence) of the Mosaic covenant was the covenant of grace but the accidents (form) of it were related to the covenant of works. He said the covenant of works and covenant of grace were both operative at Sinai.
Samuel Bolton said that the Mosaic covenant was not a covenant of works for salvation. He also denied that it was a specific administration of the covenant of grace. He taught that it was a third sort of covenant – a unique covenant of works added to and subservient to the covenant of grace. Bolton’s position, in his view, helped him maintain a distinction between the law (covenant of works) and the gospel (covenant of grace).
Samuel Rutherford disagreed with Bolton; he rejected the notion that the Sinaitic covenant was a third sort of covenant. However, he agreed with Bolton by teaching that it was not a covenant of works for salvation. Rutherford’s position was similar to Polanus’ (above). He said that the Sinaitic covenant had a pedagogical function and therefore called it a legal administration of the covenant of grace (a term that other Reformed teachers also used).
Francis Turretin taught, similar to Ames, that the Mosaic covenant was, in substance (essence), an administration of the covenant of grace. The accidents (form), showed that it was also legal covenant, the covenant of works. Turretin also emphasized the pedagogical principle of Sinai: it was meant to lead people to reject their own righteousness and flee to God’s mercy. By teaching this, Turretin upheld the law/gospel distinction.
Brown also summarizes the views of other leading Reformers, including Owen, Witsius, Dickson, Sibbes, and so forth. Again, my summaries above are essentially summaries of Brown’s summaries – you’ll have to get the book and trace the footnotes if you want to read these things for yourselves from the original sources in detail.
A few points are worth noting here. First, it is clear that in the history of Reformed theology, various positions on the Mosaic covenant have been accepted. Second, it is clear that most (if not all) leading Reformed theologians affirmed both the covenant of works and covenant of grace. Third, we also can see that these important theologians saw a law/gospel distinction at work in the Sinaitic covenant. These things are very important for us in Reformed/Presbyterian circles to remember today as we discuss covenant theology. Historical theology can teach us a lesson! As long as we agree upon the doctrines of the covenant of works and grace as the Westminster Standards explain them, as long as we maintain a law/gospel distinction and as long as we uphold the solas, we can allow for some diversity when it comes to the finer points of the Mosaic covenant.
The above information was taken from Michael Brown’s summaries in chapter three of Christ and the Condition.