The first issue is that a smaller family means a bigger State, as the government steps in to care for the aged (with ‘care for’ redefined as ‘killing’, when the money runs out.) The obverse is naturally true: a bigger family means a smaller State. (And more ways to resist the Saviour-State as well.)
The second issue is that a bigger family means a bigger family network, and more ways for family to help family… instead of crying out to Our Masters.
When my wife and I brought each of our three children into the world, we were well aware that we were giving the gift of a brother or sister to our other children. At the time, however, I did not fully appreciate how much the gift was multiplied. Each of our children was a gift of a niece or nephew twelve times over, and the gift of a cousin sixteen times over.
The family is most local of all communities, and its decline is at least as great a social calamity as the commercialization of culture and the state organization of society. In the case of the family, at least, it is in our power to effect something of a restoration.
When you have another child, you fill out the tree, and help restore the culture.
After salvation, what is the number one way for the average man to both exalt God, and pour contempt on His enemies? What is the best way for Christians to infuriate their enemies?
Get and keep a job (or better, your own profitable business), get married, have many children, and rigorously teach them all to obey God’s Law-Word continuously, by word and deed, when you rise up, and when you sit down.
And thou shalt teach them diligently unto thy children, and shalt talk of them when thou sittest in thine house, and when thou walkest by the way, and when thou liest down, and when thou risest up.
– Deuteronomy 6:7