What is the importance of filial piety, and will one who fails to show it be held accountable?

Children are a trust [amanah] given to their parents, and parents will be questioned about them on the Day of Judgment. Parents must act righteously towards their children [yabirru abna'ahum], and there are many forms of righteousness. Some are obligatory, for which the father will be questioned and held accountable for any shortcomings, while others are recommended.