As Gentiles starting converting to Paul’s form of Christianity, (For he was an apostle to the Gentiles only) the basis of conversion was on the teachings of Paul and not the teachings of the 12 apostles of Jesus. The teaching of both were very different.
Whoa... not so fast. Galatians 2 :
"Then after three years I went up to Jerusalem to see Peter, and abode with him fifteen days. But other of the apostles saw I none, save James the Lord's brother....
Then fourteen years after I went up again to Jerusalem with Barnabas, and took Titus with me also... And I...communicated unto them that gospel which I preach among the Gentiles...lest by any means I should run, or had run, in vain. .....they who seemed to be somewhat in conference added nothing to me...they saw that the gospel of the uncircumcision was committed unto me, as the gospel of the circumcision was unto Peter... to the apostleship of the circumcision, the same was mighty in me toward the Gentiles.
And when James, Cephas, and John, who seemed to be pillars, perceived the grace that was given unto me, they gave to me and Barnabas the right hands of fellowship;"
Pistolpete: If your assertions are true, why didn't the other apostles add anything to Paul when he went to Jerusalem to check if the message he had been preaching was the same as the one the other apostles were preaching?