This is why Jews are Jews and not Christians, among many other reasons, but I don't think I ever really learned the historical reasoning for the rejection at the time of his death. Whether you believe Jesus is the son of God, he was a real person.
I just don't understand how and why exactly they didn't believe he was the son of God, and how they managed to survive for so long not believing it.
Read the entirety of John 8.
They hated him because he told the truth. And they had him tortured and killed for it to protect their monopoly on being "God's Chosen" (Titus did his best to set them straight)