All this is one of God’s merciful arrangements. He gives your children a mind that will receive impressions like moist clay. He gives them a disposition at the starting-point of life to believe what you tell them, and to take for granted what you advise them, and to trust your word rather than a stranger’s. He gives you, in short, a golden opportunity of doing them good. See that the opportunity be not neglected, and thrown away. Once let slip, it is gone forever.
Beware of that miserable delusion into which some have fallen, that parents can do nothing for their children, that you must leave them alone, wait for grace, and sit still. These persons have wishes for their children in Balaam’s fashion; they would like them to die the death of the righteous man, but they do nothing to make them live his life. They desire much, and have nothing. And the devil rejoices to see such reasoning, just as he always does over anything which seems to excuse indolence, or to encourage neglect of means.
I know that you cannot convert your child. I know well that they know who are born again are born, not of the will of man, but of God. But I also know that God says expressly, ‘Train up a child in the way he should go,’ and that he never laid a command on a man which He would not give man grace to perform. And I know, too, that our duty is not to stand still and dispute, but to go forward and obey. It is just in the going forward that God will meet us. The path of obedience is the way in which He gives the blessing. We have only to do as the servants were commanded at the marriage feast in Cana, to fill the water-pots with water, and we may safely leave it to the Lord to turn that water into wine.
-J.C. Ryle in The Duties of Parents (1888)