Raising children is all about faith, because ultimately, you cannot control what they do.
No matter what you have taught them, no matter how you have disciplined them, no matter how good an example you have set (and let’s be honest, none of us do any of those three things perfectly), your children can choose to turn from the path on which you have tried to set them.
That’s terrifying. It can be disheartening.
That is why the idea of this passage (inspired by the Puritan Christopher Love) from Living Zealously is so important:
Therefore the zealous parent will make more use of the power of prayer than the rod of correction, be more in his prayer closet that at his parental lectern, and will talk to God about his children more than to his children about God.
We can water all we want, but only God can give the increase. And if we really believe in the power of prayer, and in the One who responds to those prayers, we would dedicate much more of our time for that activity.
All of the other things are important, and we should not be negligent of our duties. We should till and water our garden with diligence. However, without prayer, all we are doing is expecting things to grow without sunlight. Might as well try to catch rainwater with a colander.