As water standing behind an earth dam, and finding an aperture, washes it wider and wider and filters through it, if we do not strengthen the dam, or strengthen it insufficiently, at last, with growing weakness on our part and with repeated efforts, the water gets through with greater and greater force, so that at last it becomes very difficult, and even impossible to stop it; so also with malice hidden in the heart of man: if we let it pierce through once, twice, and thrice, it will pour out more and more powerfully, & may at last break through and overflow your dam.
St. John Chrysostom, in considering the misfortune both of parents that neglect the good upbringing of their children and of the children not well brought up, says this, 'Parents that neglect to bring up their children as Christians, are most heinous murderers of children' (Homily 3, 'Against Those that Slander the Monastic Life '). For child-killers separate the body from the soul, but these parents cast them both soul and body info fiery Gehenna. It is impossible to escape from the former death according to natural law, but it would be possible to escape from the latter death were the negligence of the parents not to blame for it. Moreover, once it comes, the Resurrection is able to abolish bodily death, but nothing can overturn spiritual destruction. Therefore, parents, listen to the word of the Lord, 'Bring up your children in the nurture and admonition of the Lord' (Eph. 6:4).