Historically Christians have taken five views of how our Christianity should be lived in society at large.
One view is that our life with Christ ought to be completely separated from those who do not share our faith and thus Christians shouldn’t mingle with non-Christians at all. Such a view point was lived out in monastic life and also in communities like the Amish who live separate from the rest of society.
The second view that the Church has had is to assimilate into culture allowing the culture to set the standards and the church to adapt to whatever those standards may be. This view is usually associated with those who are often identified as liberal Protestants.
A third view is that is that Christ ought to reign above culture in such a away that often lends to the ideology of institutionalizing Christianity into society as was done by Constantine. The Reformation challenged this idea and yet some still maintain this way of thinking.
The fourth view is found in the writings of Martin Luther in that Christ and Culture are in paradox and the two worldviews are always at odds and one only has authority over certain aspects of culture and the other has authority over others but the tension always remains between the two. The Christian, Luther argues, is to live out Christian morality in private by self-governance through love, but the secular world will still need enforceable laws to keep it in order.
The last view on this topic is that Christ transforms culture. This view dates back to the writings of Augustine, but is mostly found in Protestantism as espoused by John Wesley, John Calvin, and Karl Barth, as well as the Great Awakening ministers. In the twentieth century this view was championed by a missionary named Lesslie Newbigin. This approach follows the idea that God’s truth works for all people and shouldn’t be kept to the Church, but given to society to help transform society very much unlike an institutionalized Constantine way of looking at it. It is the view that God has principals that can help any society work better to maintain freedom, peace, justice, and happiness.
These principals when put into effect can create a healthier culture. But this view does not impose these principals, but works to teach them and show their validity by example. This is not a view that seeks to merge church in state, but a view that seeks to give contribution from the church to the culture in which it serves.
This last view has not been practiced much in Christianity, but is now gaining momentum in the modern Church. This last view is one I agree with in that Christians have something to offer the world and that something cannot be forced or institutionalized, but it can be freely given to those who are interested to try it out. If we really do know God and really do hear from Him then we shouldn’t keep that locked up inside our private sector, but offer it to those seeking to make the society we all live in better. However, within this view is the idea that if someone is offering a solution to society that works really well that the church should champion that person’s solution even if that person isn’t a Christian. People can tap into God’s order and God’s principals even if they are not Christian and Christians should recognize and get behind anyone who is working to make our society healthier.
(Source for Historical Data: Christianity’s Dangerous Idea: The Protestant Revolution by Alister McGrath : Oxford Professor, theologian, historian, and biochemist)