The second thing that stands out is the king's immediate response: humble repentance. When God points out a sin in our lives, that should be our response as well, even though our instinct may tell us to run and hide.
But God is gracious. And, as He heard King Josiah's repentant prayer, He hears ours as well.
Father God, thank You for Your grace. Thanks for forgiveness. And thank You for Your Word. May I not neglect it, but live according to it.