Colin Gunton, in The Christian Faith has a chapter on “Christian Community and Human Society” which I have found helpful in understanding the vision and purpose of the church.  He says:

“The church is the society whose distinctive way of being in the world – distinctive polity, we might say – is oriented to God primarily in terms of thanksgiving and worship. As we have seen, this is not to be understood narrowly but as an offering of all life, so that the question of the nature of the church is best approached by means of a discussion of the kind of social order that it represents. And it is as follows. The church’s way of being in the world is one that corresponds to Israel’s way of being while allowing for the changes that are consequent upon the movement from particular nation to a community incorporating all peoples.”

In other words, the church carries on Israel’s calling to worship God by the way they interact with each other and order their social life together. That social life was lived and proclaimed by Jesus (and summarized in the Sermon on the Mount) as He came announcing the Kingdom of God. As Gunton says:

“…the words and actions which maintain the church in relation to [Jesus] are those which seek to embody in its structures the form or pattern of his career. In that light, the church is a way of being socially whose life is ordered to God by means of words and actions which are evoked by the Spirit’s action.”

How we live together as a church is worship. How we care for, commit to, and interact with each other is our calling out from the world for the sake of the world. We bring glory to God and witness to the lost by our concrete ways of loving each other and orienting our lives around each other as brothers and sisters in God’s kingdom.