“If there had been nothing wrong with that first covenant, no place would have been sought for another.” Heb.8:7.
It may sound almost heretical to look at the Old Testament and say, “Something was wrong!”, but it was the writer to the Hebrews who said it— it is an inspired judgement.
I puzzled over what could be “wrong”. It couldn’t be the laws themselves—they were given by God. It couldn’t be the physical nature of the laws, because God made matter and pronounced it “good”.
My next step was to compare the old and new covenants in Hebrews 8, and I found at least a dozen contrasts drawn by the writer, including: an earthly sanctuary versus a greater and more perfect tabernacle; a tabernacle made with human hands versus a sanctuary “not of this creation”; the people did not remain faithful versus God will put his laws in their minds and they will all know him; a repeated sacrifice once per year versus one sacrifice forever; animal sacrifices versus better sacrifices; and finally, gifts and sacrifices that were unable to clear the conscience of the worker versus eternal redemption.
The last contrast seems to be the key to what was wrong— everything the Israelites did in obedience to the law never gave them a permanent right standing with God. Ezekiel tells us that a wicked man, by changing his behaviour, could live; equally, a good man could do evil and die. Ezekiel 3:20-21. Nothing was forever, and that was wrong. By Christ’s sacrifice on the cross better promises were established, all need for sacrifice was finished, and He redeemed us forever. Heb. 9:12.