I was rereading J. Gresham Machen’s Christianity and Liberalism and was struck by the following quote as it relates to several things but principally its relation to politics.
A solid building cannot be constructed when all the materials are faulty; a blessed society cannot be formed out of men who are still under the curse of sin. Human institutions are really to be molded, not by Christian principles accepted by the unsaved, but by Christian men; the true transformation of society will come by the influence of those who have themselves been redeemed (158).
Missio Dei 
While this statement is true there could be some nuance that is needed. Many Christians, in the time that this book was written, were shocked by the general decay of culture and because if this you had two factions. Those who tried to change the Gospel to attempt to change the culture, and those who ran with the Gospel away from the culture. Both were wrong.
My point is lets not read this in a twentieth century fundamentalist way.
For the record I think this is a beautiful quote nonetheless. Also all the Machen works I have are placed on a special shelf of “Favorite Authors”. so I have high regard for him.
Great insight Sok. And yes I agree we should neither be like the Liberals to changed the Gospel so it looked like the culture nor like the Fundamentalists who took the Gospel away from the culture. But rather we need to be taking that Gospel into culture to transform inviduduals within culture.