Then after fourteen years I went up again to Jerusalem with Barnabas, taking Titus along with me. I went up in response to a revelation. Then I laid before them (though only in a private meeting with the acknowledged leaders) the gospel that I proclaim among the Gentiles, in order to make sure that I was not running, or had not run, in vain. But even Titus, who was with me, was not compelled to be circumcised, though he was a Greek. (Galatians 2: 1-3)

Male circumcision is a premier sign of covenantal relationship with God specificed in Genesis 17. For the early church circumcision came to symbolize a much broader issue: loyalty to tradition or openness to revelation.

There were those who perceived the gospel as renewing the core orthodoxies of an ancient faith. These believers welcomed all ready to conform to the fundamental instructions of that faith.

Paul understood Christ to have transformed the ancient faith, opening it to a new covenant more needful of revelation than tradition. For fourteen years he preached this gospel to the uncircumcised.

When Paul went to Jerusalem it was his own decision and as the result of revelation. The orthodox authorities did not call him. Paul came to Jerusalem as a peer in teaching and preaching the gospel.

The Greek involving "running in vain" is as convoluted as the English. But a reasonable sense might be, to ensure that his ministry would not end with him. Paul sought to bind together orthodoxy and revelation.