>Before the coming of this faith, we were held in custody under the law, locked up until the faith that was to come would be revealed. So the law was our guardian until Christ came that we might be justified by faith. Now that this faith has come, we are no longer under a guardian. So in Christ Jesus you are all children of God through faith, for all of you who were baptized into Christ have clothed yourselves with Christ. There is neither Jew nor Gentile, neither slave nor free, nor is there male and female, for you are all one in Christ Jesus.
As you can see, this is speaking to a non-physical, spiritual identity, stating that we can all receive the Love and Salvation of our Lord Jesus Christ. To argue that - as they would - that the meaning of this passage is as they acclaim - is to argue against the existence of women here in the physical, earthly realm.
Moving forward with further information the biblical separations between the races, I would add the point that God created man with the power and ability and desire to create nations, and identities for the societies and races which he hath formed, and even stated to us that nations - and by extension nationality and national identity will exist even up until the end of the world, where in the book of Revelation it is said that:
>After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands (Revelation 7:9)
Therefore the concept of a nation - and a nation as WE know it - with its own language, identity, etc will be - and is MEANT TO BE - with us until the end of time.
But you ask yourself - why are there the different races on this earth, and how could one know with certainty that they are not intended to be intermixed from a biblical standpoint, leaving aside purely pragmatic evidence to include the statistics of crime and social problems which inevitably rise from this action taking place? To this valid question I would answer with this abbreviated passage of Genesis 11:1-9 kjv which gives us the TL;DR of the tower of Babel:
>And the whole earth was of one language, and of one speech. And it came to pass, as they journeyed from the east, that they found a plain in the land of Shinar; and they dwelt there… And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name… And the LORD said, Behold, the people is one, and they have all one
language; and this they begin to do: and now nothing will be restrained from them, which they have imagined to do. Go to, let us go down, and there confound their language, that they may not understand one another’s speech. So the LORD scattered them abroad from thence upon the face of all the earth: and they left off to build the city. Therefore is the name of it called Babel; because the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth.