What is a local church and is planting under an existing church a biblical mandate?

A local church is a group of Christians who gather regularly with communal identity, accountability, teaching of God's word, worship, and prayer. It can be five people in a living room or thousands in a building. There is no biblical mandate requiring a church plant to be authorized by an existing church, though such accountability brings wisdom and balance. Danger: home churches and small plants can become totalitarian environments where a single leader controls thought and life. Accountability to outside bodies can be healthy, but overarching organizations sometimes wrongly block church planting out of competition fears. Winger defaults to allowing new fellowships to flourish. The greatest danger in church planting is pride — leaders who are certain they are right about everything soon fight among themselves and division follows.