The following articles come from a book by James Montgomery Boice, Acts: An Expositional Commentary (Grand Rapids, MI: Baker Books, 1997), 319–326.
In 1978 Roger S. Greenway, a professor and former missionary to various parts of the world, published Apostles to the City: Biblical Strategies for Urban Missions. This book considers the shift of the world’s populations to the cities in our time, and it is helpful for studying Acts because toward the end of the book the author rightly focuses on the strategy of Paul in reaching cities. I say “rightly” because of all the people in the Bible who worked in cities and had a strategy for urban evangelization the apostle Paul heads the list.
As I study Acts, I sense that at the beginning Paul probably had not carefully worked out his urban strategy. He had some ideas about reaching major cities. But when he started out he seemed simply to be visiting one community after another and not to be particularly focused on cities. However, as time went on Paul came to recognize that if the world was going to be reached effectively, it would have to be through ministry to the major cities of the empire.
Today, even more than then, we live in a world of cities. And the task we face in bringing the gospel of the supernatural redemption of humanity through the work of Christ to secular people is the challenge that faced Paul.