For he is our shalom, who made both one, and broke down the middle wall of partition, having abolished in the flesh the hostility, the law of mitzvot contained in ordinances, that he might create in himself one new man of the two, making shalom; and might reconcile them both in one body to God through the cross, having killed the hostility thereby. He came and preached shalom to you who were far off and to those who were near. For through him we both have our access in one Spirit to the Father. - Ephesians 2:14-18
Jews have this 'wall of partition' called Mechitza. If you go to an Orthodox Jewish wedding, you'll see there is a drape or a wall separating the men from the women> that is mechitza. If you go to an Orthodox Jewish concert you'll find a mechitza again that will separate women from men. If you go to Ha Kotel (The western wall) you'll find a mechitza that separates men from women. When there was a Beit haMikdash (Temple) there was a mechitza that separated men from women and then another mechitza that separated Jews from goyim (non Jews).
When Paul is talking about the middle wall of partition he is referring to the mechitza that was in the Beit HaMikdash.
Yeshua came to brake down the mechitza that separated men from women and Jews from goyim, He didn't come to break down the mechitza that separates us from sin, because He made that one even stronger. Yeshua didn't come to break down the limits within we must stay in order to be holy, He just broke down the mechitza within the Beit HaMikdash that made a difference between men and women and between Jews and goyim. That's why it's written in Galatians 3:28 'There is neither Yehudi nor Yevanit (Greek), there is neither slave nor free man, there is neither male nor female; for you are all one in Massiach Yeshua. '
Mechitza that was taken away is now allowing the goyim to be together with the Jews and worship the same God, but it doesn't mean in any way assimilation of the Jews. It was grace that goyim were allowed in the same place as Jews but somehow goyim got it into their head that they were allowed in the place where only Jews were allowed to take away the Jewishness of the Jews. That is wrong on every level. Taking away the mechitza was meant to give freedom to those that had no freedom to come close to a place that they didn't have access before, not to go in there and kick out the Jews and 'decorate' the holy places as if they always belonged to the goyim. Goyim were allowed in to give up the worshiping of their gods and worship the God of Israel, they were allowed in the holy place to worship, not to change the ways of the Jews that were already in there to which Adonai gave these things to be an eternal law (Ex 12:17, Ex 27:21, Ex 29:9, Lev 3:17, Lev 16:29, etc.).
Bat Melech בת מלך