The people of Yisrael had a long history of forgetting what made them Holy. It was God who made them holy. They didn’t make themselves holy. They also lost sight of the fact that being declared tame or unclean doesn’t make one sinful or wicked either.
Yeshua’s frequently argued with the Pharisees over their emphasis on their man-made traditions over the plain word of scripture and how their man-made traditions were doing more to keep people away from God than brining them into God’s embrace.
Even after Yeshua’s death and resurrection, these false ideas about the inherent holiness of the Jewish people and the inherent wickedness of the Gentiles was hindering God’s goal to lift up, bring near, make clean, declare holy believers from the nations in the same way Heaven does for the “native-born.”