What would the twelve apostles have taught Paul if he had gone back to Jerusalem?
The twelve would have drummed into Paul what they had been preaching: that Jesus was the Messiah of Israel, the Son of God; that though He was crucified, God raised Him from the dead; and that He remained willing to be King of Israel if Israel would repent. God kept Paul from that contact so he would learn from heaven instead.
Les explains that as soon as God saved this Jewish religious zealot, He did not permit him to have contact with the twelve. He purposely kept Paul from them and sent him into Arabia, where for three years he received revelations from the Ascended Lord that he could take to the Gentile world. Had Paul gone back to Jerusalem, the twelve would have drummed into him what they had been preaching: that Jesus was the Messiah of Israel, the Son of God, crucified but raised from the dead, and still willing to be the King of Israel if Israel would only repent. But God said, no, Paul, that is not where I want you to learn. He would show Paul these things from His own position in heaven.
Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
More Questions
Did Paul go straight to Jerusalem to check with the twelve apostles after his conversion?
Galatians does not say that Paul immediately went up to Jerusalem to check his revelation out with the twelve.
Did Paul go back to Peter and the other apostles to learn what they knew?
After those three years God did not send Paul back to the Twelve to pick up everything they knew; Paul was not an extension of Peter and the Eleven's ministry.