I have not followed the book, but there are a few things here that maybe entered my mind as I refer to your post. God made a eternal covenant with Abraham that He would have a covenant community whose number would be like the visible stars in the sky. His promise was carried out by a sacrifice which the animal was cut in two and God walked in-between the animal showing it was Him alone that would complete the action of the covenant to His people. He is always faithful, His loving kindness is evermore that is He is full of faithful love, and He never makes a mistake. The faithful remnant constantly walked in the covenant love of God not in the active obedience to the moral law. Even tho it was difficult because of all of the sacrifices. There was a moral demand for obedience to the eternal covenant. The reasonable demand came through the moral law, was given by Moses after the eternal covenant had been made. Since the law was absolute,  breaking the law would bring an eternal curse on the responsible people. Moses was the high priest for the people before God. The chosen people made an agreed to obey the law fully. But because of sin, the Israelites could not meet the requirements. God provided a necessary sacrifice. But their sincere hope was ne'er through the moral law. It was perpetually through the eternal promises in the everlasting covenant. For the necessary requirements for the Israelites to promptly obey, they reasonably required the necessary sacrifice to amply atone for their sins. God required daily sacrifices for sin. The sacred blood was constantly gushing. Although there was no possible way that they could meet the requirements of the moral law, Gods covenant promises were repeatedly met! And through divine grace He satisfactorily established an efficient way for the Israelites to meet the requirements. He generously provided a necessary sacrifice. They no longer had to fear God in the pagan way. In the eternal covenant they had access to God through graciously offering a necessary sacrifice to amply atone for their sins. Yet there was only a faithful remnant of the in that judicial church out of all of the nation of Israel who setting up heathen idols. The faithful was carefully kept by the faithfulness of God in the eternal covenant. Presently we have a better covenant. God promised to properly capture the heart of stone out of us and place a new heart by His Spirit. He would cause us to pace in His ways. He promptly sent Christ to adequately represent the ultimate fulfillment of the moral law and sent His Spirit on the new Church. He promptly opened the direct access to the Father because of His sacrifice was "once for all." We are made new creatures and walk in a new way, thru doctrinal instruction, thru doxology or praise, we overcome all opposition. It is a considerably better covenant.