He was very interested in the equality of Jew and gentile. That is, people coming in to Christianity from non-Jewish religions. That was his major concern, without doubt. He took over this phrase, we know, from an earlier baptismal formula. In this case, I think at least, probably, we can't take it as a wonderful slogan for equality, although women today would like to use it that way, and maybe they can go ahead and use it whatever Paul meant by it.
Some people suggest that the early Christian movement was an egalitarian one.
I'm not so sure of that. It does seem to me that when it was a marginal movement, when it was dangerous to belong to it. So it seems that the movement took anybody that it could get, and depended on them in ways that much more established groups, like for example, the Jewish community of a wealthy town like Sepphoris , might not have allowed. Obviously we have sources that suggest that these were enormously live issues. The Gospel of Mary Magdalene , for example, shows us a Christian community in which Mary Magdalene is regarded as a disciple, as a leader, as one of the major teachers in the group.