Should the Jews have recognized Jesus as the Messiah from the Old Testament?
Yes. Israel had the Old Testament prophecies looking forward to their Redeemer, King, and Messiah, and after 1,500 years under the Law they should have known who He was. The Old Testament was full of it, but they were steeped in unbelief.
Les explains that Israel was under the Law since Exodus chapter 20, and the Law was a schoolmaster to bring them to the place of justification by faith, not by law-keeping. All through the Old Testament, the prophecies looked forward to the coming of their Redeemer, King, and Messiah. Therefore, they should have known who Jesus was, and they could have known who He was, because the Old Testament was full of it. But they did not because they were steeped in unbelief.