Legacy

Proverbs 22:6 says, "Train up a child in the way he should go; even when he is old he will not depart from it." But what happens when you do exactly that, and your child walks away from the Lord. And in contrast, how do some really solid Christians come from atheist parents? We may strive and work to leave a godly and good legacy for our children and grandchildren, but that doesn't guarantee that they will follow in our footsteps. Why is that and how do the ancient kings of Judah illustrate exactly this?