My dear Brother Ian, I think we are in more agreement than appears. This is a complex subject because like the Jews of old, we are not well grounded. Teachers have not been very good at presenting the truth as it is in Jesus. I think that we agree on the gospel truth, but where the difficulty comes in is with the language of Paul. I am not an expert on this, but I have been praying and studying and have found that others are seeing the same as what I believe I am seeing. It is the language that Paul used that is difficult for us. He was speaking to "Old Covenant" Jews or those that had come under their teachings. We are not in that same position so we place a different meaning on his words, I think.
The Old Testament precedes the Old Covenant which was made at Sinai. The Old Testament is the Bible from the beginning of Genesis when there were no Jews. One third of Earth's history was before Sinai and the Old Covenant. Only one third of history was bound by the Old Covenant if we agree that it ought to have ceased with the teachings of Paul on the subject. Of course it has not ceased, for there are many today that believe they can work their way to heaven by keeping the commandments of God. And, even after Sinai, God was still presenting the Everlasting Covenant to the Jews. He spoke His promises through the prophets which in turn were persecuted by the Jews. He also used the Sanctuary service to teach the Everlasting Covenant. But, the ceremonial law even though it foreshadowed Christ, did not save anyone anymore than the moral law could, it only was the school-master to point to Jesus.
I understand to a degree where we are having a problem. I, too, saw the Sanctuary and its services as providing salvation through Christ, but I don't believe that is what Paul was teaching. When we talk about providing salvation in Paul's language, he is speaking another language to meet the Jews on their ground, not ours. They did not perceive the Lamb as Christ. They perceived the Lamb as a lamb representing their great sacrifice, not God's. So, Paul used their idea of salvation to address their error. They wanted law, so he told them what was expected under law, perfect obedience. He told them that the letter of the law "killeth" whereas the Spirit brings life. This in no way brought reproach upon the law for he said it was glorious, but it could not save as the Jews taught that it could.
Paul is making a point that we have a hard time understanding. He is trying to point out that the law cannot save, only Christ can save. This is why he chose to use the phrases "Old Covenant" and "New Covenant". He was contrasting the Jews plan of salvation with God's plan. The Jews had taken the agreement made at Sinai as being the full plan, but it was not. It was only the law, both moral and ceremonial. God commanded them to do it. The law cannot save, but it is "part" of the plan of salvation. They took the ball and ran with it not knowing there was more to it. If they had prayerfully studied the ceremonial law, they would have learned of the full plan and their need of the Lamb that taketh away the sins of the world. Paul is going to teach them the whole plan, but first he needed to show them the error of their teaching. The blood of bulls and goats could save no man, only the blood of Christ can bring life.
I hope this helps to explain my understanding a little better. I am sure that we both will continue to better understand this as we seek wisdom from on high. Again, thank you for your patience and giving me opportunity to express what I believe to be true. As an erring human, I really appreciate your patience and your posts. The truth will not suffer from a close examination and in this subject there is so much more to learn. Thank you, dear brother.