First we need to ask "who were these that were "scattered abroad throughout the regions of Judaea and Samaria, EXCEPT THE APOSTLES." Acts 8:1. It is to this same scattering that we read further Acts 11:19,20.
It most certainly was NOT the Apostles, according to Acts 8:1. We know that those who WERE scattered abroad spoke the word to none save ONLY TO JEWS. But there were SOME of them, who, when they came to ANTIOCH, spoke unto the GREEKS ALSO.
So..what does this mean to anything? Especially to Peter and the 11 who were STILL at JERUSALEM? When the Church at Jerusalem heard of this, they sent Barnabas to look into it and HE went to Tarsus to find Saul (later called Paul), and UNDER SAUL the Church at Antioch became the BASE OF OPERATIONS FOR THE EVANGELIZATION OF THE GENTILES with "the gospel of the grace of God."
And how do we know this?
It was from ANTIOCH that Paul went BY REVELATION to Jerusalem to communicate TO THE LEADERS THERE that gospel which he preached among the Gentiles. (Gal. 2:2).
And what was the result of this meeting of Paul and the LEADERS at Jerusalem (Peter and the 11)? Peter and the 11 promised to CONFINE THEIR MINISTRY TO ISRAEL, recognizing Paul as the Apostle of the Gentiles.
What do you think the circumcision/uncircumcision problem was about? Jewish Messianic Churches preaching the gospel of the kingdom as they were commissioned to do, and the gospel of the grace of God, Paul's commission to Gentiles, meeting head on. Would Israel accept Christ as Messiah? Or would she continue to reject Him? Would Gentiles have to go through Israel to be blessed, or would God open another door for them? Would Peter and the 11 sit upon twelve thrones judging the twelve tribes of Israel at any moment Israel accepts Him and He returns to set up His Kingdom? Or would they continue to reject Him and therefore the Gentiles would be forever without hope, strangers from the convenants and aliens from the promises?
God, in His grace, in SPITE of Israel's rejection of Messiah, provided a means for Gentiles to be saved APART FROM ISRAEL: "BY THE GOSPEL".
But it is all part of the transition taking place in Acts. From law to grace, from a kingdom of believers to a body of believers, from the gospel of the circumcision to the gospel of the uncircumcision, etc. From Biblical Prophecy to a Biblical Mystery, hid in God from the foundation of the world, until revealed to the Apostle Paul. Eph. 3:2,3,5,6,9.
That's been quite a story up until this point. How about some evidence and not just layer upon layer of conjecture?
God, in His grace, in SPITE of Israel's rejection of Messiah, provided a means for Gentiles to be saved APART FROM ISRAEL: "BY THE GOSPEL".
Already handled in Matthew, Mark and Acts long before Saul's conversion.
But it is all part of the transition taking place in Acts. From law to grace, from a kingdom of believers to a body of believers, from the gospel of the circumcision to the gospel of the uncircumcision, etc. From Biblical Prophecy to a Biblical Mystery, hid in God from the foundation of the world, until revealed to the Apostle Paul. Eph. 3:2,3,5,6,9.
Quite a tale there and thoroughly unconvincing, especially when we are aware of what else lies behind the facade of this position. Your post reads like a succession from Christ to the Twelve to the minimalist churches of Jews versus a succession from Christ to Saul/Paul to the success of Christianity. The Twelve are a practice run and don't amount to much. Paul is the one to whom Christians must turn to. No.
Paul was necessary. But so was Peter. So were all the other Apostles (including Judas if you think about it).