What does Galatians 2:1 mean?

Paul is continuing to make his case to the Galatian believers that the Judaizers are wrong. This group, who insisted that Gentile converts needed to obey Old Testament law in order to be saved, were attempting to discredit Paul's authority. In the previous chapter, Paul's main point was that he had, in fact, been made a full apostle by Jesus Christ Himself without the influence of the other apostles. Now Paul will explain that, after some time passed, the other apostles agreed with him that the Gentiles—like all people—are saved through faith alone and not through following the law of Moses.

Paul begins by recalling a trip he made to Jerusalem with Barnabas, a Jewish Christian, and Titus, a Greek (Gentile) Christian. This trip seems to fit best with a trip described in Acts 11:27–30. At that time, Paul and Barnabas were sent to Jerusalem with money that was gathered up to meet the needs of the people in Judea who were suffering through a famine.

This trip likely happed fourteen years after Paul's conversion and eleven years after he went back to Jerusalem to meet with Peter for the first time.