The people in His day and age saw Him. Did they believe? Did they see God in the flesh walking with them? Teaching them? Giving them the eternal truths of life? Showing them how to live, the way to live - both by word and by example? Were they just so overwhelmed by the awe of knowing that this was God? He even proclaimed Himself as being such! Were they so overwhelmed that they said, Yes, I see. I believe. I'm going to follow. No. The Bible's own witness is that they did not know Him, even though they saw Him.
Just because one sees does not mean that one is going to believe. That is because, in the biblical sense, there is a spiritual aspect to seeing and believing. The scripture here indicates that there was not even a flash of recognition as to His true identity.
Now look at Jesus Christ for just a minute in your mind's eye. The most unique Personality that ever lived in the history of mankind! A one of a kind. The only human being who ever lived life sinlessly. And, yet, He could not be identified even by those who saw Him. He was not recognized when God was in the flesh and sharing life with the people of His generation.
All of this seems to indicate that one has to be predisposed to receive this belief - this ability to see. It is interesting, in the context of verses 12 and 13 especially, that those who exercised this faith…
That is, to enter into a relationship with God that results in nothing less than the creation of a new being.
The woman—Israel—“took” of pagan belief systems from the nations around her and subtly introduced those corrupting ways into her relationship with God. The Judaism that Jesus encountered was a spiritually deadly blend of some Scripture, plus beliefs and practices absorbed during the Babylonian captivity, flavored with Greek philosophy, and baked with the traditions of previous generations. The problems Jesus encountered were false beliefs, and hearts hardened by doctrines and practices that were far removed from God’s intent.
What Jesus encountered demonstrated a thoroughly leavened relationship, such that “He came to His own and His own did not receive Him” (John 1:11). The parable teaches that the covenantal relationship between God and Abraham’s family kingdom had completely degenerated, and thus, the leavening in this parable is consistent with the idea of corruption.
The implication of that scripture is that He came to His own family—the Jews—and they did not "recognize" Him. Do you know why? At least part of the reason is because they were not familiar enough with the Old Testament descriptions of what the Messiah would be like, to be able to recognize Him when He did come. You know the story. They were looking for a conquering king who would kick the Romans out. [They were] completely deceived, completely turned away from the truth of God's Word.