From The Off Ramp:
With this view, “mission” shifts from naming a function of the church to describing its essential nature. In a missional church, the church IS mission rather than does mission as a program or activity of the larger life of the church. The church’s nature is to show the world what it looks like when a community of people live under the reign of God in every aspect of daily life. As Robert Webber states in The Younger Evangelicals, the church “is an alternative culture that points to the kingdom of God and the reality of the new heavens and the new earth.”...in a missional community, the church is God’s sent people. That means when everything is stripped away – the building, the events, the activities, the leaders, and other identifying markers for the church – the people are the church and church is the people. Therefore, wherever God’s people are corporately or individually, there is the church. Church is at home, in the car, in the restaurant, the beach – wherever God’s people find themselves in their daily lives.
And more. A good introduction to what it means to be missional.