Church Planting
Acts 14:21-23
And when they had preached the gospel to that city, and had taught many, they returned again to Lystra, and to Iconium, and Antioch, Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the kingdom of God. And when they had ordained them elders in every church, and had prayed with fasting, they commended them to the Lord, on whom they believed.
The Pattern
The New Testament teaches that church planting is the responsibilty of local churches. It is the local church's responsibility because the Great Commission (Matthew 28:18-20) was given to the church.
We see examples of this throughout the New Testament, most notably with the Apostle Paul. He was sent out by the church at Antioch to preach the Gospel and start churches in other cities. He, and others with him, started churches all over the known world. Those churches reproduced other churches.
We see this in the lineage of our own church, how one church sent out laborers to start new churches and propogate the Gospel.