God chose Abraham to give rise to the nation of Israel. He said, "I will bless them that bless you, and I will curse them that curse you."
Jesus came to the Jew first. The rest of us were grafted into the true vine.
In Romans, Paul rhetorically asked, then immediately answered his own question. "Hath God forgotten his people? God forbid, for I too am an Israelite (Jew). But they are blinded in part for a season until the time of the Gentile be fulfilled.
Salvation is first to the Jew, then the Greek (Gentile)
As far as the Jews scorning and ultimately crucifying Jesus, I believe Jesus would say that He gladly laid down His life to make recompense for my sins, the Jews sins, your sins. It was me, my offense of infinite justice which nailed Jesus to the Cross. To all who would come to Him.
For dispensationalists, we now are in the dispensation of Grace (unearned, unmerited favor with God, not because of anything we did or who we are, but because of Jesus and what He did at the Cross. He went to the Cross in spite of my sinful ugliness...Because of who He is and in spite of who I am.
There seems mystery in this, but I think it is the crux of Gods plan.
Texas Songwriter- thanks for your comments. They are helpful and insightful.