When God's people (the Jews) were invaded and forced into exile to a foreign land during the 6th century B.C., God gave them this counsel:
ESV Jeremiah 29:5 Build houses and live in them; plant gardens and eat their produce. 6 Take wives and have sons and daughters; take wives for your sons, and give your daughters in marriage, that they may bear sons and daughters; multiply there, and do not decrease. 7 But seek the welfare of the city where I have sent you into exile, and pray to the LORD on its behalf, for in its welfare you will find your welfare.
In other words, people of faith are not to let their heads float in the clouds. People of faith don't ignore the places where God has put them to live, simply longing for heaven and hunkering down until Jesus' return of their death. Rather, let us serve well. Let us seek the welfare and improvement of the society around us. There will be many defeats and hard blows, but the rare and small victories are worth it. Let us seek the welfare of our neighborhoods, communities, cities, country, and the world to the glory of God . . . or as Jesus taught us to pray, "Our Father, who art in heaven . . . Thy kingdom come, Thy will be done!"
See a good write up by Charles Colson on what that means for our country today here.