The Bridges of God by Donald McGavran - Ch. 3

McGavran seems to make quite the supposition in this chapter. He postulates that Jews in one city corresponded with their relatives in another city so that when Paul showed up in Corinth, he had a ready audience. McGavran never really gives any evidence for this from scripture except to say that Paul saw conversions, and because Peoples are converted via familial connections, McGavran states, this must have been the case for Paul. I'm not so sure about this. I feel like McGavran is reaching to give a Biblical support to his conjecture about the proper way to do missions in the non-Western world.