John Stott remarks that mission is at the heart each of the five parts of the Bible.

1. The God of the Old Testament is a missionary God, calling one family in order to bless all the families of the earth.
2. The Christ of the gospels is a missionary Christ; he sent the church out to witness.
3. The Spirit of the Acts is a missionary Spirit; he drove the church out from Jerusalem to Rome.
4. The church of the epistles is a missionary church, a worldwide community with a world-wide vocation.
5. The end of the Revelation is a missionary End, a countless throng from every nation.

Stott concludes: ‘Mission lies at the very heart of God and therefore at the very heart of the church.  A church without mission is no longer a church.  It is contradicting an essential part of its identity.  The church is mission.’

Authentic Christianity, p315f (numbering added)