On sharing

For the possession of goodness is by no means diminished by being shared with a partner either permanently or temporarily assumed; on the contrary, the possession of goodness is increased in proportion to the concord and charity of each of those who share it. In short, he who is unwilling to share this possession cannot have it; and he who is most willing to admit others to a share of it will have the greatest abundance to himself. (Augustine City of God p483, emphasis mine)

In the gospel, foolishness is proclaimed. The way to have more is by sharing; the way to have less is by hoarding. This must be impressed upon children from infancy, for the world will consistently tell them the opposite - and indeed, apart from the gospel, the opposite is true.