We tend to overlook that Jesus preached to Israel, and He said that He had other sheep to gather, not of that flock. God has not turned away from Israel, but rather has blessed all nations through Abraham.
There is a time of restoration for Israel, a time when He will be King of all. This time is said to last for a thousand years, and then comes the end, and judgment.
If we have stood in His presence, and witnessed His glory with our own spiritual eyes, then we will not be arrogant towards anyone, no matter where they are from, whether Jew or gentile, no matter what they have done. In His presence, seeing His perfection, and knowing our sin, we can only be humble.
History is replete with those who have decided that Israel has been cast aside by God, but His promises are forever, and are efficacious without our efforts. Otherwise our salvation is not real. If God has turned away from Israel, then His promise to us who are gentiles is of no count.
By the grace of God, through His Son, may we all know the humility which sees each and every person as one whom Jesus sacrificed His life for, in obedience to His Father's commandment.
My earnest prayer is that we all become one in Him, bound together in the love of God through His Spirit.