From Joel Comiskey's blog:
Early Christians and Houses
by Mario Vega
The house played an important role in the early decades of Christianity. In the first century the house was the main place where people lived and worked. Today it is quite different since people only live in their homes. For this reason, it is difficult for us to imagine how central the home was back then since it as the main center of operations.
Back then, when people were converted, often the entire household believed in Jesus. On other occasions, Jesus told his followers that he would bring division between members of the same household–between those who followed him and those who refused to do so. The truth is that in one way or another, the houses were the line that constituted the difference between faith and unbelief.
From the beginning it was through the houses that the church engaged the world. The background of the house definitely influenced the theological reflection of the early Christians. To them, it was like following the model of Jesus who developed his ministry in houses. Therefore, it should not be surprising that after the resurrection of Jesus the Church gathered in the upper room of a house (many believe this was the same upper room where Jesus and the disciples celebrated their last Passover together). The disciples wanted to continue the tradition that Jesus had initiated.
From Jerusalem on, the expansion of the gospel happened from house to house, city to city and nation to nation. Thus, the gospel transformed individual households and eventually the entire world.
Today, the family is still the foundation of society. If Christians believe this is true, we have more reason to continue to sow the seed of the gospel from house to house.