They were written by Jews....I guess that solves the problem.
It is interesting what Jesus said of the religious leaders of his day....
" Jerusalem, Jerusalem, who kills the prophets and stones those who are sent to her! How often I wanted to gather your children together, the way a hen gathers her chicks under her wings, and you were unwilling. 38 Behold, your house is being left to you desolate! 39 For I say to you, from now on you will not see Me until you say, ‘Blessed is He who comes in the name of the Lord!’” (Matthew 23:37-39)
Jesus was highlighting the fact that Israel's history concerning the prophets that God had sent to them in the past were ignored and silenced. He came to heal the Jewish people, but the Jews who adhered to the teachings of the Pharisees did not want to be healed. They had acted just as their forefathers had done and we believe that they killed the last prophet that God sent to them. There would be no more.
Jesus took the "lost sheep of the house of Israel" and separated them from a corrupted religious system that was based on the traditions of men and the unlawful twisting of scripture.
Actually Christendom is a mirror image of Judaism. Just as the Jews persecuted the Christians in the beginning, the Christians ended up persecuting the Jews....and each other....but not by following the teachings of Jesus Christ. His teaching was to "love God with all your heart and love your neighbor as yourself". Jesus was of course quoting the Hebrew scriptures.....these were the only scriptures he had.
Jesus was never sent to the Gentiles...he was sent exclusively to his fellow Jews. The gathering of the Gentiles came after his death and resurrection. This was in fulfillment of God's covenant with Abraham for the blessing of all nations through the coming seed. (Genesis 22:18)
Politically, there seems to be nations who support Israel because they seem to think that hanging onto Israel's coattails, they will get a blessing for their efforts. (Zechariah 8:23) I personally don't believe that applies in the political sense. I believe it applies spiritually.
What brighter future do Jewish people look forward to today? Israel is hardly enjoying peace is it? What do you expect the future to hold for you all?