I preached this past Sunday on the idea of being "sheltered." Our church has been in a series of sermons called UnChristian based on a book of the same title. The book is all about the negative perceptions that outsiders have of Christianity and Christians. Each sermon has addressed a specific way that Christians have typically acted unchristian.
So I talked about the perception that Christians are "sheltered." Many outsiders use words like old-fashioned, boring, club-like, out-of-touch and irrelevant to describe Christianity. Its easy for us as Christians to get into our "christian bubble" and remain there. This is not good, because Jesus calls us to be more than a member of a club and do more than just hang out with other Christians.
Jesus calls us to be salt and light in the world. He challenges us to engage people with the same love and wisdom he did. When we are sheltered, we aren't doing that. We are called to be "unsheltered." To be engaged and involved in people's lives and in the culture around us.
Ask yourself how you are sheltered (because most of are in some way) and then seek ways to move out of it. When you do, you will fulfillment, purpose and blessing.