When God took away their land, their temple and their king, He promised them that one day, He would make a New Covenant with the house of Israel and the house of Judah. (Jeremiah 31:31-34) This New Covenant would in fact be the fulfillment of God's ancient promise to Abraham, to being blessing to all the nations on earth through Abraham's offspring.
In the New Testament, God sent His Son to His own people, but they did not receive Him. The night before His crucifixion, Jesus passed a cup of wine to His disciples, and with words that echoed Moses, He inaugurated the promised New Covenant. He said, "Drink from it, all of you; for this is My blood of the covenant, which is poured out for many for forgiveness of sins." (Matthew 26:27-28)