Galatians 2:1

These men he had as witnesses, through whom he proved that his gospel was given to him through revelation, seeing that he said "Barnabas went up with me," and he also took Titus, whose faith and gospel were approved by everyone.

His first journey was owing to his desire to visit Peter, his second, he says, arose from a revelation of the Spirit. "And I laid before them the Gospel which I preach among the Gentiles, but privately before them who were of repute, lest by any means I should be running or had run in vain." What is this, O Paul! thou who neither at the beginning nor after three years wouldest confer with the Apostles, dost thou now confer with them, after fourteen years are past, lest thou shouldest be running in vain? Better would it have been to have done so at first, than after so many years; and why didst thou run at all, if not satisfied that thou wert not running in vain? Who would be so senseless as to preach for so many years, without being sure that his preaching was true? And what enhances the difficulty is, that he says he went up by revelation; this difficulty, however, will afford a solution of the former one. Had he gone up of his own accord, it would have been most unreasonable, nor is it possible that this blessed soul should have fallen into such folly; for it is himself who says, "I therefore so run, as not uncertainly; so fight I, as not beating the air." (1 Cor. ix: 26.) If therefore he runs, "not uncertainly," how can he say, "lest I should be running, or had run, in vain?" It is evident from this, that if he had gone up without a revelation, he would have committed an act of folly. But the actual case involved no such absurdity; who shall dare to still harbor this suspicion, when it was the grace of the Spirit which drew him? On this account he added the words "by revelation," lest, before the question was solved, he should be condemned of folly; well knowing that it was no human occurrence, but a deep Divine Providence concerning the present and future. What then is the reason of this journey of his? […]

(Chapter 2 - Verses 1, 2) Then after fourteen years, I went up again to Jerusalem with Barnabas, taking Titus along also. I went up by revelation, and I discussed with them the gospel that I preach to the Gentiles, but privately with those who seemed to be influential, so that I might not be running in vain or have run in vain. This matter arose because of false brothers secretly brought in, who slipped in to spy out our freedom that we have in Christ Jesus, so that they might bring us into slavery.

I did not come, he says, to be taught, but to inform; which brings only honor to him.

After commending the authority of the Gospel teaching according to itself in the preceding chapter, the Apostle now in this chapter commends it on the part both of the other apostles and of himself. About this he does two things: First, he commends the authority …

But we may readily conclude, that, after they had been brought to believe the gospel, some time must have elapsed before that dispute about the ceremonial law arose. I consider, therefore, that the fourteen years are to be reckoned, not from one journey to another, but from Paul's conversion. The space of time between the two journeys was eleven years.

Then fourteen years after - My first journey thither. I went up again to Jerusalem - This seems to be the journey mentioned Acts xv, 2; several passages here referring to that great council, wherein all the apostles showed that they were of the same judgment with him.

Peter was the apostle to them; and the ceremonial law, though dead with Christ, yet not being as yet buried, he connived at the respect kept up for it. But Paul was the apostle of the Gentiles; and, though he was a Hebrew of the Hebrews, yet he adhered to pure Christianity.

Then fourteen years after I went up again to Jerusalem,....

This he knew was a doctrine that would be ungrateful to many there, and yet he was not afraid to own it, but in a free and friendly manner lays it open before them and leaves them to judge whether or no it was not the true gospel of Christ.

The decree would not at all disprove their view, and therefore would have been useless to quote. Paul meets them by a far more direct confutation, "Christ is of no effect unto you whosoever are justified by the law" (Ga 5:4), [PALEY].

Then fourteen years after - There is a considerable difference among critics concerning the time specified in this verse; the apostle is however generally supposed to refer to the journey he took to Jerusalem, about the question of circumcision, mentioned in Act 15:4-5, etc. These years, says Dr. Whitby, must be reckoned from the time of his conversion, mentioned here Gal 1:18, which took place a.d. 35 (33); his journey to Peter was a.d. 38 (36), and then between that and the council of Jerusalem, assembled a.d. 49 (52), will be fourteen intervening years. The dates in brackets are according to the chronology which I follow in the Acts of the Apostles. Dr. Whitby has some objections against this chronology, which may be seen in his notes. Others contend that the journey of which the apostle speaks is that mentioned Act 11:27, etc., when Barnabas and Saul were sent by the Church of Antioch with relief to the poor Christians in Judea; there being at that time a great dearth in that land. St. Luke’s not mentioning Titus in that journey is no valid objection against it: for he does not mention him in any part of his history, this being the first place in which his name occurs. And it does seem as if St. Paul did intend purposely to supply that defect, by his saying, I went up with Barnabas, and took Titus with me also. The former St. Luke relates, Act 11:30; the latter St. Paul supplies.