41 But the question may be asked, how He called the fishermen from their boats two by two, namely, calling Peter and Andrew first, and then going forward a little and calling other two, namely the sons of Zebedee, according to the narratives of Matthew and Mark; whereas Luke's version of the matter is, that both their boats were filled with the immense haul of fishes. And his statement bears further, that Peter's partners, to wit, James and John, the sons of Zebedee, were summoned to the men's help when they were unable to drag out their crowded nets, and that all who were there were astonished at the enormous draught of fishes which had been taken; and that when Jesus said to Peter, “Fear not, from henceforth you shall catch men,” although the words had been addressed to Peter alone, they all nevertheless followed Him when they had brought their ships to land. Well, we are to understand by this, that what Luke introduces here was what took place first, and that these men were not called by the Lord on this occasion, but only that the prediction was uttered to Peter by himself, that he would be a fisher of men. That saying, moreover, was not intended to convey that they would never thereafter be catchers of fish. For we read that even after the Lord's resurrection they were engaged again in fishing. The words, therefore, imported simply that thereafter he would catch men, and they did not bear that henceforth he would not catch fish. And in this way we are at perfect liberty to suppose that they returned to the catching of fish, according to their habit; so that those incidents which are related by Matthew and Mark might easily take place at a period subsequent to this. I refer to what occurred at the time when He called the disciples two by two, and Himself gave them the command to follow Him, at first addressing Peter and Andrew, and then the others, namely, the two sons of Zebedee. For on that occasion they did not follow Him only after they had drawn up their ships on shore, as with the intention of returning to them, but they went after Him immediately, as after one who summoned and commanded them to follow Him.
Source: The Harmony of the Gospels (New Advent)