We refer to the Jews as God's chosen people, but never ask,"What were they chosen for? Are they something like teacher's pet with special privileges? Or were they chosen to accomplish something important?" The answer is that they were chosen to be the conduit through which God would bring the Messiah into the world--to provide salvation to the entire world, not just the Jews. They fulfilled that mission through the birth of Jesus, but subsequently failed to recognize it. Now that their primary mission has been completed, they are on an equal playing field with the rest of the world. Accept Christ and be saved, or reject Christ and be lost. No special treatment.
Jews are descendants of Abraham. God made a pact with Abraham because he listened. First God proved that he could believe in what he couldn't see by leading him away from everything he knew. Then God made special promises to him because he listened. This promise bound both of them. Part of the promise was the sign of circumcision to show the promise carried on to offspring.
Then God asked his blood bound partner to sacrifice his son. Somehow this covenant between them gave God a correct path to have his own supernatural born son, just like Abraham and sacrifice him, just like Abraham.
The purpose of the whole thing was to give God the correct path to save the world through Jesus. That's why Jews are the chosen people and why Jesus gave them first refusal rights.
