Many people have failed to see that there was more than one covenant involved at Mt. Sinai. God called Moses up into the mountain before He gave the law and proposed a covenant between Him and His people: "And Moses went up unto God, and the Lord called unto him out of the mountain, saying, Thus shalt thou say to the house of Jacob, and tell the children of Israel; ... if ye will obey my voice indeed, and keep my covenant, then ye shall be a peculiar treasure unto me above all people: for all the earth is mine: And ye shall be unto me ... an holy nation. These are the words which thou shalt speak unto the children of Israel." Exodus 19:3-6.
Notice how God asked Moses to present His offer to the people. Here are all the elements of a true covenant. Conditions and promises are laid down for both sides. If the children of Israel accept God's proposal, a covenant will be established. How did they respond to the divine offer? "And Moses came and called for the elders of the people, and laid before their faces all these words which the Lord commanded him. And all the people answered together, and said, All that the Lord hath spoken we will do. And Moses returned the words of the people unto the Lord." Exodus 19:7, 8.
Just as soon as that answer went back to God, the basis for the Old Covenant was set up. But before it could go into formal operation there had to be a sealing or ratifying of the pact. This ritualistic service involved the sprinkling of the blood of an ox on the people and is described in Exodus 24:4-8:
Again we are reminded that this covenant was not the law itself but was made "concerning all these words." The Ten Commandments were the basis for the agreement. The people promised to keep that law, and God promised to bless them in return. The crucial weakness in the whole arrangement revolved around the way Israel promised. There was no suggestion that they could not fully conform to every requirement of God. Neither was there any application for divine assistance. "We can do it," they insisted. Here is a perfect example of leaning on the flesh and trusting human strength. The words are filled with self-confidence. "All that the Lord hath said will we do, and be obedient."
Were they able to keep that promise? In spite of their repeated assurances, they miserably broke their word before Moses could even get off the mountain with the tables of stone. Do we begin to see where the poor promises lay in the Old Covenant?
The book of Hebrews begins to unfold. There God is reported as "finding fault with them." Hebrews 8:8. He said, "Because they continued not in my covenant ... I regarded them not." Verse 9. The blame is placed squarely upon the human side of the mutual pact. Thus, we can see exactly why Paul wrote as he did about this Old Covenant in Hebrews 8. It did gender to bondage, it proved faulty, had poor promises, and vanished away - all because the people failed to obey their part of the agreement. Putting all these things together we can see why a new covenant was desperately needed, which would have better promises.
How were the New Covenant promises better? Because God made them, and they guaranteed successful obedience through His strength alone. "I will put my laws into their mind ... I will be to them a God ... I will be merciful to their unrighteousness and their sins and their iniquities will I remember no more." Hebrews 8:10-12.
How was the New Covenant ratified? In the same manner that the Old was confirmed - by the shedding of blood. But instead of an ox having to shed its blood, the sinless Son of God would provide the blood of sprinkling: "Now the God of peace, that brought again from the dead our Lord Jesus, that great shepherd of the sheep, through the blood of the everlasting covenant, Make you perfect in every good work to do his will, working in you that which is well-pleasing in his sight, through Jesus Christ." Hebrews 13:20, 21.
What a contrast to the weak promises of the flesh made by Israel at Sinai. Instead of the people's "we will do," God's New Covenant promise is to "make you perfect in every good work ... working in you." It is no longer human effort. It is not so much you working, but Him "working in you." And how is this power made available? "Through the blood of the everlasting covenant." Because of what Jesus did on the cross.