Romans 11:15: For If Their Rejection Means The Reconciliation Of The World, What Will Their Acceptance Mean But Life From The Dead?
 For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? (ESV)
The Jews had rejected the Gospel of Jesus Christ. Some had received Him, but for the most part the Jewish nation had hardened their hearts to the truth. In some ways it seems natural that the ones who were responsible for placing the Son of God on a cross would not want to admit their guilt. It is human nature that we do not like to admit our wrong. Imagine having to admit such a great error.
As the Jews rejected the Gospel message the doors were opened to the Gentiles. Paul's life as a missionary to Gentile nations is recorded in the book of Acts. In every town he offered the Gospel first to the Jews. Once they rejected his message he offered it to the Gentiles where it was in many cases received with joy.
Paul tells us in Romans 1:16 the order in proclaiming the Gospel. He said, "For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek. (Romans 1:16)" This was not only Paul's belief, but it was his practice everywhere he went. What was the Jews' response? They rejected the Gospel.
The Jews' rejection of the Gospel opened the door for the reconciliation of the whole world. Now, Paul poses that at such time as the Jews accept the Gospel it will be so grand it will be like a resurrection from the dead. Paul is not talking here about literal resurrection, but he compares their ultimate acceptance of the Gospel as to the wonder of the resurrection.
Thank God for his ultimate plan for bringing people unto himself. If you have heard the Gospel, but never accepted it's message why not place your faith in him right now? You can know the wonder of having your sins forgiven and the hope of eternal life.