The Size of the Early House Churches
Church historians agree that house churches could rarely have been more than 15 or 20 people—simply because they took place in small apartments. The vast majority of people, perhaps as many as 90 percent, lived in apartments of one or two rooms crowded above or behind shops. Once a house church grew larger than that, it multiplied by simply starting another house church nearby. If not, the growth immediately caused problems.
Normally a house church met in the largest room of a private home, usually the dining room. Most apartments shared a public courtyard with adjoining units, and families cooked in the courtyards. The dining room and courtyard provided space for teaching and preaching ministries, baptismal instruction, prayer meetings, the celebration of the Lord's Supper, and missional activities. Privacy was rare. Wayne Meeks writes that life happened in front of the neighbors. In our privatized world, it's hard to imagine what the early church experienced.
One of the major cultural gaps between then and now is the extended family, or the ancient oikos structure. Those who live in the Western world have a hard time imagining the New Testament culture in which it was normal to live with parents, relatives, servants, and other workers. We are accustomed to living in nuclear families—father, mother, and children. Yet, the ancient world didn't even have a way to express what we call the "nuclear family." We only find the word oikos, which means household, house, or extended family.
God used the oikos to extend the gospel throughout the Roman Empire. The early believers modeled transformed lives and distinct values that were often countercultural. Yet, in these crowded, urban environments, people were able to see Christianity up close. They heard and saw the testimonies of those transformed by the gospel, and they desired to experience Christ for themselves. Husbands loved wives, servants were treated with dignity, married partners submitted to one another, and love reigned supreme. Friends and neighbors were drawn to this new transformed community.
Developing Leaders Organically
Many are amazed at how quickly Paul developed leadership in the early church, but the early house churches were natural incubators for leadership. In Paul's church plants, we don't see formal leadership structures. The person who opened his or her home would assume leadership, and the rest of the leadership structure was already in place—Paul used the oikos structure that was already built into the social infrastructure.
Those leaders were only later given titles. In 1 Thessalonians 5:12-13, Paul says, "Now we ask you, brothers, to respect those who work hard among you, who are over you in the Lord and who admonish you. Hold them in the highest regard in love because of their work." Paul is talking about house church leaders, but he didn't feel it was worth mentioning their exact title because they developed organically within the house-church structure.
Nowhere in the New Testament do we find a picture closely resembling any of the fully developed systems of today. Church government was not very highly developed, and local congregations were rather loosely knit groups. House churches in the New Testament existed side-by-side with other house churches. Individual believers and house churches considered themselves part of a greater citywide church. Church ministry was fluid and dynamic. Members were encouraged to experience their spiritual gifts for the common good of the body, and leaders operated as gifted men and women (Romans 12:6-8; 1 Corinthians 12:8-10, 27-28). This led to many opportunities for ordinary people to develop into leaders.