Howard Snyder in Decoding the Church writes of missional church in chapter 3. The missional church is genetically missional, an alternative community, a covenant community, and Trinitarian.

Genetically Missional

The church is genetically missional because it is the community of Jesus Christ, God’s great missionary. It is the body of Christ, the community called into existence by the mission of God. this is the starting point for all ecclesiology… Mission is the church’s DNA, even if mission often gets suppressed in practice. This means three things:

1. The church has a mission TO God as well as FROM God. The church is called to “represent God’s reign as its community, its servant, and as its messenger.”

2. Evangelism has a special place in the church’s mission. Evangelism, in its basic and broadest sense, means announcing and embodying the reign of God.

3. Preaching the gospel to the poor is a special priority for the church. Jesus said he was anointed by the Spirit to “preach good news to the poor” (Luke 4:18).

An Alternative Community

A missional church is an alternative community called to build its own culture, economy, and lifestyle in the world and among all peoples. A faithful fchurch is a visible alternative to both neopagan society and to ecclesial models of Christendom that clash with the church’s basic DNA… The church is an alternative community when its mission is the kingdom of God. Its mission makes it countercultural. ANd it is an alternative reality when it exists as a covenant community.

A Covenant Community

A mssional church is covenantal. The church is the covenanted community of God’s reign. The covenant calls the church to ministry and mission, to “equip [God’s people] for the work of ministry (Eph 4:12) and to structure its life and mission accordingly. A covenant community focused on ministry and mission must pay attention to several key points.

1. To be a covenant community, the church must have some form of covenant groups.

2. The biblical meaning of member needs to be rethought. Today “member” has an exclusively organizational sense. The NT, however, speaks of “members of the body,” not of “membership. With few exceptions, the original organic meaning of member — “a part of the body” — has disappeared… the NT says nothing about “joining the church.”

3. The split between clergy and laity must be overcome in concept and practice.

4. Healthy covenant communities teach and practice plural leadership.

5. The theology and practice of ordination needs to be rethought.

6. Church structure (wineskins) must be consistent with the organic nature of the church.

A Trinitarian Community

A missional church is Trinitarian. The Trinity teaches us about ecclesiology and mission. Because the church is Trinitarian — based on what God the Father has done and will do through Christ by the power of the Spirit — the church is at the same time incarnational and eschatological.

1. The church is a Trinitarian worshipping community. The church in its worship worships Father, Son and Holy Spirit, and the Trinity forms the basis of the church’s mission as the community responds to the call of the Trinity to participate in the missio Dei. In worship the community draws near to God and comes to understand the Father’s creative love and care for all He has made, the Sons’ self-giving in becoming a servant for our salvation, and the Spirit’s call and push to go into the world as the Father has sent the Son. (54)

2. The Trinitarian community is sent especially to the poor. Though “being in very nature God,” Christ “made himself nothing, taking the form of a servant” (Phil.2:6-7) and carried out his mission. This is a demonstration of the wisdom of God, for God “chose the foolish things of the world to shame the wise; God chose the weak things of the world to shame the strong. He chose the lowly things ..the things that are not.. to shame the things that are..” 1 Cor. 1:27-30. (55)

3. The whole ministry of the church is grounded in the Trinity. All ministry.. ordained, non ordained, pair or unpaid.. is rooted in the Trinitarian mystery. Its roots are in Spirit-empowered community, not in organizational hierarchy. The Trinity is the opposite of hierarchy (56)