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.
A lot of people began to wrongly believe that the coming Messiah would be establishing an earthly kingdom (that comes later) and free them from Roman rule. Over the 400 years between OT and NT, the belief likely evolved from the Israelites losing their powerful kingdom because of their forefathers sins, and the wishful thinking of wanting it back. Imagine growing up in Judea in 0 AD, you hear and read stories from when your people were the premier power in the world, your own scripture talks all about it and what happened then, while you live in a token state on the edge of civilization after 10/12's of your people were permanently scoured from the land God gave you. You'd probably put a lot of faith in the coming Messiah, which Isaiah describes as a conqueror and king.
They just completely missed Isaiah 53, which is just a minor issue /s