In short, I will preach it [the Word of God], teach it, write it, but I will constrain no man by force, for faith must come freely without compulsion. Take myself as an example. I opposed indulgences and all the papists, but never with force. I simply taught, preached, and wrote God's Word; otherwise I did nothing. And while I slept or drank Witternberg beer with my friends Philip and Amsdorf, the Word so greatly weakened the papacy that no prince or emperor ever inflicted such losses upon it. I did nothing; the Word did everything. Had I desired to foment trouble, I could have brought great bloodshed upon Germany; indeed, I could have started such a game that even the emperor would not have been safe. But what would it have been? Mere fool's play. I did nothing; I let the Word do its work.
How do we change the culture (s) in which we live? We don't. The Word does. We simply preach it, teach it, write it, and live out radical lives changed by the Word in the culture in which we live.
How do we change the culture of our churches? We don't. It is not about our programs or music style or whatever else you would like to throw against the church wall to see if it sticks. It is the Word of God that will change the culture of our churches. We must have faith that the Word of God will do the work of God among the people of God.
It really is that simple.