They say that missionary kids do not feel at home either in their family culture or the culture their parents serve in: they are 'third culture kids'. One of the strengths of such a perspective is that you can see the faults of both cultures; one of the weaknesses is that you never feel at home in either.
Every Christian should be 'third culture' in two ways: (1) we find ourselves critical of the culture in which we live and (2) our home is not in this world.
Concerning the first, Christians should be aware of how much their culture has been shaped by The Narrowing (the so-called enlightenment) - and how much they have imbibed that spirit.
Our individualism is a chief sign of that influence. As Western born-again believers, we just cannot see the New Testament's insistence that we think and act as a body, as a community, rather than as individuals. Every decision we make affects the people around us. For example, when we join in we encourage our brothers and sisters, when we stay away we discourage them (Hebrews 10:25).
This individualistic attitude is an inheritance straight from The Narrowing. (Yes I know it goes further back to the Fall....). These thinkers (1680s-1780s) believed that human reason alone, not faith or tradition, should guide human conduct. "Have courage to use your own reason" was their motto. "The Enlightenment valorized the individual and the moral legitimacy of self-interest." (The Portable Enlightenment Reader, p.xii).
The Western Church is profoundly affected by this attitude. We make decisions without due concern for or reference to their impact on others. This is one reason the Western church is so weak. Instead of working together as a body, Christians often act as dismembered limbs and body parts: not a pretty sight, not very functional either.
It is a real blessing to experience the reverse! And in the Western church there are blessed examples of groups of believers who have, by the Word and Spirit, been made sensitive to their interconnectedness and the impact of their actions upon others and who love each other as family members do.
They are true 'third culture' Christians who have seen the sinful self-centredness of their own culture and in obedience to Christ come to truly love their eternal family.