"There is no difference" -- heresy in his own day.  For Paul showed that in God's eyes there was no race problem: "all have sinned," and all are "justified freely."   There are not two paths to God, nor is there a single path with a "Jews Only" sign on the gate.  Instead -- and this is the point that drove his enemies to murderous rage -- God solved the problem of Gentile unrighteousness by setting aside the Law which created two categories of humans, and substituting His son Jesus Christ, in whom all men and women are unified when they believe:

            For he himself is our peace, who has made the two one and has destroyed the barrier, the dividing wall of hostility, by abolishing in his flesh the law with its commandments and regulations. His purpose was to create in himself one new man out of the two, thus making peace, and in this one body to reconcile both of them to God through the cross, by which he put to death their hostility (Eph 2:14-16).

            This revelation, which is what it was -- not an idea of human poetic imagination, but a Divine impartation -- was repeated in several of Paul's epistles:

            I appeal to you, brothers, in the name of our Lord Jesus Christ, that all of you agree with one another so that there may be no divisions among you and that you may be perfectly united in mind and thought (1 Cor 1:10)

            For we were all baptized by one Spirit into one body--whether Jews or Greeks, slave or free--and we were all given the one Spirit to drink. (1 Cor 12:13)

            Here there is no Greek or Jew, circumcised or uncircumcised, barbarian, Scythian, slave or free, but Christ is all, and is in all  (Col 3:11).

This is the great theme of his ministry, not just the proclamation of the Gospel of salvation, but of the racial consequences of that Gospel.  It is not possible to talk accurately about the Pauline mechanics of individual salvation (hearing the Word, repentance, faith, confession, receiving the Spirit) and neglect the corporate consequences.  For Paul, a Jew who believed in Jesus as Messiah could not continue under the Law.  Instead, he would find himself thrust into a new congregation composed of mixed-race people, who shared his own faith but not his background, and over whom he had no superiority.  And these people would be his new brothers and sisters, taking the place of his former co-religionists, who were people of like blood and language.  Could anything more socially revolutionary be imagined?

Obviously, this did not play well in Jerusalem, where the ties to the old community remained strong.  Elsewhere, the new congregations could not be built on an Old-Covenant foundation, because that foundation was alien to Gentile believers.  The new ecclesiastical order had to be Gentile in nature, so that it would not be intimidating to pagans and polytheists.  Yet it was Paul's intent that these churches not only stand in continuity with the Old Testament teaching, but that they inherit the promises God had made to national Israel:  His Presence among them, His favor on them, and His Kingdom in their midst.