If the gospel is to challenge the public life of our society, if Christians are to occupy the "high ground" which they vacated in the noontime of "modernity", it will not be by forming a Christian political party, or by aggressive propaganda campaigns. Once again it has to be said that there can be no going back to the "Contantinian" era. It will only be by movements that begin with the local congregation in which the reality of the new creation is present, known, and experienced, and from which men and women will go into every sector of public life to claim it for Christ, to unmask the illusions which have remained hidden and to expose all areas of public life to the illumination of the gospel. But that will only happen as and when local congregations renounce an introverted concern for their own life, and recognize that they exist for the sake of those who are not members, as sign, instrument, and foretaste of God's redeeming grace for the whole life of society.
A few pages later, Newbigin mentions a survey that was conducted in Bangalore, India, which revealed that the majority of lay members felt that the clergy were too involved in business outside the congregation, while the majority of clergy felt that they were not involved enough. I'm not trying to make anything of the lay/clergy dichotomy here (plenty of clergy are inwardly focused, while plenty of lay people are outwardly focused). But I think when you get right down to it, when folks ask "what is this word 'missional' supposed to mean", this is the ultimate in-a-nutshell bottom line: does the church exist for the sake of its members, or for the sake of those who are not members? Obviously, the answer is "both", but the "mission" of a "missional church" (again, in a nutshell) is to move that balance ever further toward "those who are not members". The only way to do this is to form "members" into disciples of Jesus Christ who are committed to the Great Commandment and the Great Commission. It sounds so easy.... ;-)
"With God, all things are possible."