Shall I hide from Abraham what I am about to do, since Abraham will surely become a great and mighty nation, and in him all the nations of the earth shall be blessed? For I have chosen him, so that he may command his children and his household after him to keep the way of the Lord by doing righteousness and justice, so that the Lord may bring upon Abraham what He has spoken about him (Gen.18:17-19).
God spoke these words about Abraham and his family, a year before Isaac was born (Gen.21:1-3). He really had received amazing promises from God, which all have great relevance to us, in the New Testament era (see Ro.4).
Abraham had received grand promises from God, and been remarkably visited by Him. Abraham now (like us), was wholly dependent on God’s promises coming about. He still had a lot of living to do, and he (like any other godly person) longed to see God’s promises to him, fulfilled.
As North writes,
Children were important to Abram, not merely because of the cultural standards of the Canaanite tribes that surrounded him, but because of several distinctly theological reasons. First, the gift of children was important for the preservation of the covenant line prophesied by God to Eve (Gen.3:15). It seems quite probable that Abram knew about this prophecy to Eve (Jn.8:56). Second, the task of cultural dominion was (and is) intimately linked with the expansion of human numbers (Gen. 1:28; 9:1). Third, a man’s heirs-intellectual, spiritual, and biological- are part of his concern for linear history…
The faith of the Old Testament saints was to be in linear, irreversible historical development, controlled by God. Men and women were to play an important role, in time and on earth, as parents. This work had meaning because of God’s covenants and requirements.
Clearly, the education of Abraham’s children (and Isaac was still unborn), would be firstly theological in nature. They would need to be taught the Word of the Lord.
We know that Abraham had access to this, because many years after he died, God appeared to Isaac. As we might expect in these Genesis visitations by God to the patriarchs, God made promises to him, and linked these to the fact that
…Abraham obeyed Me and kept My charge, My commandments, My statutes and My laws (Gen.26:5).
Let’s be frank. We’ve not really begun to educate our children, until such time as they understand the basics of covenant theology: that God was in Christ, reconciling the world to Himself (II Cor.5:19), and that as believers in Jesus, there is great hope and promise for our children.
Is there more?
Of course, but that will get them off the mark. Now, they simply need the implications of this shown to them, firstly from scripture, and secondly, in the lives of their parents, and others.
Paul spoke about this to Timothy. He said he was
…mindful of the sincere faith within you, which first dwelt in your grandmother Lois and your mother Eunice, and I am sure that it is in you as well (II Tim.1:5).
So, no school, eh? Correct.
Education? Yes, but not school.
Schools commonly harm children. Every year, my work brings me into contact with children that were harmed at school: lots of them. That could be the peer-group, the curriculum, or the teachers. But parents shouldn’t wait for that to happen, before home schooling them. Lot’s daughters were schooled in Sodom, and how did they work out? (See Gen.19).
Does that mean that in the home, we can eliminate errors and pain? No. Abraham couldn’t, as we can observe through his experience with Ishmael. How could we?
But God tells us that
Behold, children are a gift of the Lord, the fruit of the womb is a reward. How blessed is the man whose quiver is full of them; they will not be ashamed when they speak with their enemies in the gate (Ps.127:3-5).
We parents pass from this life, leaving others behind. We are responsible for how they are prepared for life, which means that God holds us to account. And by His great grace, we can do this. In fact, we are commanded to do so.
Is that what you’re preparing for?
 Gary North, “The Dominion Covenant,”1987, p.163, 164.