let's look at what Paul is trying to say. He says in v. 2, "I went there because God revealed to me that I should go. While I was there I met privately with those considered to be leaders of the church and shared with them the message I had been preaching to the Gentiles. I wanted to make sure that we were in agreement, for fear that all my efforts had been wasted and I was running the race for nothing."
a. Paul would not have gone to Jerusalem if the Lord had not told him to do so since he was not concerned with the soundness of his teaching (Luther, 48).
b. However, he still wanted to be in agreement with the leaders in the church. If Paul felt the need for agreement, then it makes sense that we should be in agreement.
c. When Paul reached Jerusalem, he simply submitted (from anatithēmi, to lay something before someone for consideration) to them the gospel which he had always preached among the Gentiles, the gospel of salvation by God's sovereign grace through man's penitent faith—a gospel utterly contrary to the works-righteous belief of the Judaizers that "unless you are circumcised according to the custom of Moses, you cannot be saved."
(John MacArthur, MacArthur New Testament Commentary – Galatians, WORDsearch CROSS e-book, 35).
d. His gospel did not demand adopting the Jewish way of life and did not include submission to the law. Paul even states that he did this humbly: "for fear that I was running or had run my race in vain."
e. This was a grand concession on Paul's part. However confident he was in the revelation that he thought was from Jesus Christ, he was still willing to submit his revelation to the evaluation of the leaders of Jerusalem (McKnight, 83).
4. The church leaders were so in agreement with Paul, "they supported me and did not even demand that my companion Titus be circumcised, though he was a Gentile."
a. Although Titus is never mentioned in the the Book of Acts, from Paul letter's we know that he was one of Paul's converts, and became one of his close companions (Fung, 86).
b. Titus, a true Christian, was living and incontrovertible proof that circumcision and Mosaic regulations are not necessary for salvation.
c. It should be noted that some years after that occasion Paul circumcised Timothy "because of the Jews who were in those parts" (the region of Galatia), but he did so because Timothy was half Jewish.
d. He was not making a concession to the Judaizers, but rather was giving Timothy closer identity with Jews to whom they might witness.
e. Timothy was circumcised as a Jew not as a Christian. His circumcision had no relationship to his salvation but simply gave him entrance to Jewish synagogues, from which he would otherwise have been excluded (MacArthur, 38).
f. There was nothing wrong with being circumcised, but to insist upon it as a condition for salvation would be a slap in the face of God's grace (Luther, 51).
5. However, we need to be cautious whose counsel we seek.