“Where in Christianity (or some other belief system, if you subscribe to such) do you find the idea that every family must guarantee that it will be a self-sufficient economic unit, in perpetuity, before the family can have a child?”
Can’t remember anyplce in the Bible......is common sense a gift of God like free will?
My common sense says that it’s pretty much impossible, in this unpredictable universe, for anyone to know what’s going to happen to him tomorrow, let alone make guarantees for an entire human life of perfect self-sufficiency.
Nor do I think it should even be a goal. From the beginning of our existence, as a single cell, we need another to survive, and we need others to thrive. Every day of life depends on the sufferance of others: someone could have run the stoplight and killed me this morning, someone may decide to shoot me this afternoon.
Imagining that we run things is idolatry.