In Gal. 2:2-9 we read that when Paul went up to the leaders at Jerusalem to communicate to them "THAT GOSPEL which I preach among the Gentiles, (v.2), they "saw" (V. 7), and "perceived" (v.9) that God had indeed entrusted a new revelation to him, and solemnly, publicly, officially, gave him "the right hand of fellowship" (v.9), acknowledging him as God's new apostle to the nations and agreeing to confine their own ministry henceforth to Israel.
"And when James, Cephas, and John, who seemed to be pillars, perceived THE GRACE THAT WAS GIVEN TO ME..."(v.9). They didn't teach him anything. He taught them the gospel he was preaching: the gospel of the grace of God.
Once again, it PLAINLY says what it says.
Gal 1:20 I assure you before God that what I am writing you is no lie.
Paul was a persecutor of Christ through the persecution of His followers. That he was now a convert created suspicion among those to whom he was preaching. There were those who came among them as spies to turn them over to the authorities.
It was important that he be authenticated as having the same commission and message as that of Peter and the others since they had walked with Jesus and Paul had not.
Paul had to show that what he preached was from Jesus and not from Peter and the others. Apostolic imprimatur was crucial to the reception of Paul as well as the message.
As for the revelation he went to Jerusalem to share, it was concerning circumcision of Gentile converts.
Gal 2:4 This matter arose because some false believers had infiltrated our ranks to spy on the freedom we have in Christ Jesus and to make us slaves. 5 We did not give in to them for a moment, so that the truth of the gospel might be preserved for you.
Paul had begun teaching that Gentiles did not have to be circumcised but others were disputing that saying the Gentiles had to be circumcised to be saved. Paul goes to Jerusalem to confirm that what he was teaching was true.
Gal 2:2 I went in response to a revelation and, meeting privately with those esteemed as leaders, I presented to them the gospel that I preach among the Gentiles. I wanted to be sure I was not running and had not been running my race in vain.
Accepting that Jesus had revealed this to Paul, Peter pronounces that it would be a burden to require circumcision for the Gentiles. Paul testifies to the works God has done among the Gentiles. Upon hearing what Peter had to say and hearing the testimony of Paul and Barnabas, James agrees also and calls for a letter to be written and read in Antioch.
The letter says in it:Acts 15:28 It seemed good to the Holy Spirit and to us not to burden you with anything beyond the following requirements: 29 You are to abstain from food sacrificed to idols, from blood, from the meat of strangled animals and from sexual immorality. You will do well to avoid these things.
Paul receives from the others verification of what he is teaching. Now, in Galatians when Paul is writing of this event and the council, he says that he did not need to have God’s approval, but he needed that of “those held in high esteem”, those whose opinion was acceptable and binding on the followers of the Way.
6 As for those who were held in high esteem—whatever they were makes no difference to me; God does not show favoritism—they added nothing to my message. 7 On the contrary, they recognized that I had been entrusted with the task of preaching the gospel to the uncircumcised,[a] just as Peter had been to the circumcised.[b] 8 For God, who was at work in Peter as an apostle to the circumcised, was also at work in me as an apostle to the Gentiles. 9 James, Cephas[c] and John, those esteemed as pillars, gave me and Barnabas the right hand of fellowship when they recognized the grace given to me. They agreed that we should go to the Gentiles, and they to the circumcised. 10 All they asked was that we should continue to remember the poor, the very thing I had been eager to do all along.
No where here does Paul say that he has a different gospel from that of Peter and the others. He only says that they, Cephas and John recognized that he had received the grace to preach to the Gentiles.
When I read this I see the Church at work exactly as it works now. Glory be to God.