Tom Schreiner clearly and simply explains the intricacies of the Mosaic covenant, which he calls “The Covenant with Israel.” in his book Covenant and God’s Purpose for the World. Like many scholars, Schreiner believes that the Mosaic covenant is based on grace, not works: “Some mistakenly separate it almost altogether from the covenant with Abraham and identify it as a legalistic covenant” (59). But numerous connections back to the Abrahamic covenant indicate that it is based upon God’s grace. Even the fact that Suzerain-vassal treaties begin with a recount of the great suzerain’s identity testifies to the gracious nature of the Mosaic covenant (62). Schreiner then shows that the covenant at Moab (the Deuteronomic covenant) is not a separate covenant, but a renewal of the Mosaic covenant (62-63). Schreiner points out that Israel “renewed and repledged its loyalty to Yahweh a number of times” (64). Therefore, such a covenant renewal being found in Deuteronomy is not unique.
But what about sin? Did Israel need to perfectly keep the covenant? Schreiner answers, “no.” Israel was not called to perfect obedience because the covenant “provided the means by which Israel could maintain fellowship with God” (65). The way Israel would do that was the sacrificial system. Israel was sinful and could only approach God through sacrifice.
As God’s people, Israel was called to be holy and fulfill the commission given to Adam and reconfirmed with Abraham (67). They were to mediate God’s blessing to the world through obedience to the covenant and their distinctive lifestyle (67-68). Unfortunately, Israel did not maintain its distinctiveness nor obedience to the covenant. While the Mosaic covenant contained some important connects back to the Abrahamic covenant, it also had some key differences. First, no promise of fulfillment was given in the Mosaic covenant (68). Second, the covenant was intentionally set up to be temporary (68-69). Numerous texts in the Old Testament foresee Israel’s failure to keep the covenant (Lev 26:14-44; Deut 27:15-26; 28:15-69). While Israel was brought into relationship by God’s grace, he did not grant it the ability to keep his word: “The Mosaic covenant was a gracious covenant, but the Lord didn’t provide Israel with the moral ability to keep its requirements” (70). Therefore, a new covenant would be needed.
We see then that the Mosaic covenant plays an important, but not ultimate, role in the storyline of Scripture. It was given as a way to fulfill the Abrahamic covenant but it was never intended to be the complete, consummated fulfillment.