The Mercy of God

Our high privilege is to "bring up children in the nurture and admonition of the Lord." Whatever others may say or do, Christian parents should choose for their children that "good part which shall not be taken from them." To them, everything else should be like dust.
Exhaust the weight and vigor of your effort here! Our children are heirs to immortality. They are creatures of responsibility, and are rapidly advancing to the judgment seat. Soon they will be upon a bed of death from which they will ascend to heaven or descend to hell, to the extent they sought or rejected, followed or despised their great Redeemer.
Gardiner Spring, Hints for Parents

And Tedd Tripp commenting on this section ...
We read something like the paragraphs above and our hearts say, "yes and amen," to it all. Most of us feel agreement mixed with guilt and a profound sense of our failure. The enemy of our souls is making an assault on us. He is throwing his fiery darts at us. "You can't do this stuff. You are a failure. You are so weak. You might not even be a Christian. It is too late for your kids." His desire is to overwhelm us with our failure and our guilt and fill our thoughts with doubt and unbelief.
We lift the shield of faith against these flaming arrows. And we wield the Sword of the Spirit - the Word of God.
"I am the vine, you are the branches. If a man remains in me and I in him, he will bear much fruit, for apart from me you can do nothing." John 15:5
"No temptation has seized you except what is common to man. And God is faithful; he will not let you be tempted beyond what you can bear. But when you are tempted, he will also provide a way out so that you can stand up under it." 1 Cor. 10:13
"I can do everything through him who gives me strength." Phil. 4:13
"His divine power has given us everything we need for life and godliness through our knowledge of him who called us by his own glory and goodness. Through these he has given us his very great and precious promises, so that through them you may participate in the divine nature and escape the corruption in the world caused by evil desires." 2 Peter 1:3-4
Let us remember that with all our appropriate efforts to have the shaping influences of our child's life be filled with happiness and spiritual substance, it is not those efforts or influences that will save them. That is God's work alone and he delights in showing mercy.