in today's christianity today home page tim keller exhorts us to be a "christian counter-culture for the common good." i think keller has a distinctive, theologically grounded and culturally aware perspective on how we can help bring shalom to our cities. i hope you can take a moment to read the article, but for you lazy asses i've posted an excerpt below.
"It will not be enough for Christians to form a culture that runs counter to the values of the broader culture. Christians should be a community radically committed to the good of the city as a whole. We must move out to sacrificially serve the good of the whole human community, especially the poor. Revelation 21-22 makes it clear that the ultimate purpose of redemption is not to escape the material world, but to renew it. God's purpose is not only saving individuals, but also inaugurating a new world based on justice, peace, and love, not power, strife, and selfishness.
So Christians work for the peace, security, justice, and prosperity of their city and their neighbors, loving them in word and in deed, whether they believe what we do or not. In Jeremiah 29:7, Israel's exiles were called not just to live in the city, but also to love it and work for its shalom—its economic, social, and spiritual flourishing. The citizens of God's city are the best possible citizens of their earthly cities."