Acts 13:13

Now Paul and his company set sail from Paphos, and came to Perga in Pamphylia: and John departed from them and returned to Jerusalem.

Two very important changes appear in this verse. "Barnabas and Saul," which until this point had been the designation of this missionary team, abruptly in this place gave way to "Paul and his company," or "Paul and Barnabas" as used generally in Acts afterward. Luke's coupling the defection of John Mark from the company with this marked change of leadership has been read by some as proof that John Mark's defection was due to his resentment of Paul's replacing his uncle Barnabas as the leading missionary. This, of course, is not certain; but neither is it impossible. Many people have quit their duty for reasons not unlike that. See my Commentary on Mark, p. 1, for further comment on John Mark. Whatever was the cause of Mark's defection, Paul disapproved of it and refused to take him on the next journey (Acts 15:36-41).

Perga in Pamphylia ... Although this was the destination of Paul's company when they set sail from Paphos, there is no record of anything that occurred there, Luke skipping over anything that might have taken place there, and focusing upon Paul's preaching in Antioch of Pisidia. The speculation of William M. Ramsay to the effect that Paul contracted malaria in low-lying Perga and promptly moved on to higher ground at Antioch (altitude about 3,500 feet)[20] does not appear reasonable. As MacGreggor noted:

A sick man would surely have returned to Cyprus rather than undertake the strenuous Taurus passage; and, if Paul was in fact it is more likely that the sickness came on in Antioch, compelling him to stay longer there than he had anticipated (Galatians 4:13).[21]

[20] Sir William Ramsay, The Church in the Roman Empire (New York: G. P. Putnam's Sons, 1893), pp. 61ff.

[21] G. H. C. MacGreggor, op. cit., p. 175.