Christians in the (Ancient) Cities

Lately I've been working my way through The Cambridge History of Early Christian Literature. More than anything else it is a helpful overview of the literature and social setting of early Christianity. Writing about "The Social and Historical Setting" of Christianity from its inception until the time of Irenaeus, John Behr makes the following observations about the manifestation of the distinctive movement in the cities of the Greco-Roman world.

The cities were "rife with infectious diseases, such that most people would have suffered from chronic health conditions, and those who survived had a life expectancy of less than thirty years. Cities were subject to frequent fires, collapsing buildings and other disasters. To maintain their populations, the cities needed to be repopulated by newcomers more or less continually, leading to high rates of crime and frequent riots. In such conditions, the Christian church could provide a new basis for attachments and an extended sense of family." 

Behr goes on to note that for a city, when an "epidemic struck . . .the fatalities were enormous, probably about a quarter to a third of the total population." In such conditions, the "typical response of pagans, even doctors like Galen, was to leave the cities for the countryside until the danger passed." By contrast, two early writers remarked "how the Christians, having learnt how not to fear death, remained in the cities nursing the sick. . . . Galen also noted that the Christians' 'contempt of death and of its sequel is patent to us every day.'" 

Behr concludes that the "newly forming Christian communities offered, in Stark's words, a 'new culture capable of making life in Greco-Roman cities more tolerable."" How might Christians in today's cities embody to those watching and in need a new culture?