Galatians 2: 1-2. ” Then fourteen years after, I went up again to Jerusalem with Barnabas, and took Titus with me also. And I went up by revelation, and communicated unto them that gospel which I preach among the Gentiles, but privately to them which were of reputation, lest by any means I should run, or had run, in vain.”
You can read more about this visit Paul made to Jerusalem in Acts 18. It was a very important visit because it established beyond doubt that the gospel Paul preached among the Gentiles was the same that the other apostles preached among the Jews.
Paul made this visit after certain people came from James to Antioch, where the apostles were working. These people insisted that the Gentile believers must obey Jewish rites and ceremonies; they must be circumcised, and keep the law of Moses, or they could not be saved.
When Paul came into contact with these people, he waited until he had a clear revelation (message, instruction) from God before he took Barnabas and Titus with him to Jerusalem. Paul didn’t behave impulsively here. I’m sure he spent hours in prayer and study, seeking God’s clear leading, before he made the journey.
Barnabas had come from Jerusalem to find Paul in Tarsus, to persuade him to go to Antioch and assist in the ministry there. Barnabas was a good and godly man who willingly stepped back when Paul’s leadership became apparent (Acts 11:24.)
Paul also mentioned Titus, who was a Gentile believer who had not submitted to circumcision or other Jewish rites, and Paul had not demanded that he do so (Gal. 2:3). Paul took Titus with him as a sort of “test case” for the leaders there who were on board with the Judaizers.
Paul’s primary purpose was to compare the gospel as God had revealed it to him with the gospel being taught in Jerusalem. He did not go with a haughty attitude, but rather sent word ahead of time, asking to meet with the leaders there in private. He was not on a mission to divide and conquer, but to make sure that the race he was running was not run in vain.