Interesting enough, when people are asked, What is a family?", many would say that it is basic building block of society or a fundamental unit of society. There are two ways to look at the family unit, one in a social context and another in a spiritual way.
According to Allan Carlson, president of The Howard Center, an organization which defends the natural family, the natural family is a man and woman bound in a lifelong covenant of marriage for the purposes of: the continuation of the human species, the rearing of children, the regulation of sexuality, the provision of mutual support and protection, the creation of an altruistic domestic economy, and the maintenance of bonds between the generations."
For many, a family serves to meet those purposes.
For Christians, the act of making a family is more of a commission than a desire to achieve societal efficiency. Rather than becoming just a breeding ground for human capital and storage house for material wealth, families become a building block for the Kingdom of God.
The word families does not necessarily apply only to physical members who share blood relationships. Churches and the body of Christ are a type of spiritual family in itself. The body of Christ and its members act as the building blocks to the Kingdom of God. The K.O.G. is a society which has more than God in the picture- it puts God in the center of it.
Although there are scholars who attempt to define the purpose of families, they tend to exclude its primary function- to love.
God is the source of love, according to 1 John 4:8. His Son, Jesus Christ, came to reveal His love to man.
Since the example of love through Jesus has already been shown to mankind, what remains to be done is mankind emulating that example.
Jesus once used the parable of a mustard seed to describe the process of the Kingdom of God. Just like a big tree begins with one seed, the Kingdom of God begins with one man, then one family, then one community, one nation, one people, one world.