Go to the Large Cities
Paul chose to work in the cities of the empire, not because they afforded more comforts or larger crowds, but because they were strategic centers from which the light of the gospel could spread to the surrounding regions. He began in Antioch, where he and Barnabas spent a whole year teaching the disciples (Acts 11:26). A glance at the map will immediately indicate the strategic importance of Antioch for the Christian missionary.
The third city of the empire, outranked in size only by Rome and Alexandria, crowded with a mixed population and connected commercially with both East and West, Antioch was the most important place for the faith, advancing from Jerusalem, to occupy.
From it the new religion would be carried by report in every direction. It lay just beyond the confines of Palestine, and thus was not so far from the original center as to lose touch with the mother church. At the same time it was the door from Palestine to the Graeco-Roman world. No place was so well suited to be the base of operations for the progress of Christianity into the empire.
In his three missionary journeys Paul kept pretty well to the famous Roman roads built and maintained by the state. Along these roads were situated the most important cities of the empire. All of them were the centers of Roman administration and Greek civilization.
Some of them, such as Philippi, were Roman colonies; others, such as Thessalonica, were busy commercial centers. All except Philippi had a sizable Jewish population. Athens was the cultural center and Ephesus the religious center of the empire.
Paul did not preach in all the cities along the way. He chose those which, for one reason or another, were important to his plan for the speedy evangelization of the empire. He passed through—but evidently did not preach in—Amphipolis and Apollonia on his way from Philippi to Thessalonica (Acts 17:1). Nor was his stay in each city of equal duration. In some he remained only a few weeks; in others he stayed two or three years
J. Herbert Kane, Christian Missions in Biblical Perspective