Joash is the youngest King of Judah. Taking the throne at age 7, Joash could easily have found himself immature and not ready for such a huge role of leading the nation of Judah But he was wise enough to come to his uncle Jehoiada the High Priest for advice all through Jehoiada's life.
But eventually Jehoiada dies, and Joash loses his best counsel. It is a loss that could disrupt the good that Joash was doing and, and unfortunately, it does just that. The whole story can be found in II Kings 12 and II Chronicles 24. Since you know that I am not going to paste these whole chapters here, but I desire to ensure you know my information is accurate, I will be quoting one verse from each selection:
"And Joash did that which was right in the sight of the Lord all the days of Jehoiada the priest." ~II Chronicles 24:2
"And Jehoash did that which was right in the sight of the Lord all his days wherein Jehoiada the priest instructed him." ~II Kings 12:2
Joash had an instructor in his life. He had someone who would help him be able to serve the Lord. But it would seem that once that instructor moved on (died is a form of moving on, right?), we learned that Josiah hadn't actually found any real love for God himself. He never became sufficient in God.
Hey, I understand that it is truly beautiful to have a mentor in your life. I have had my share and they have been greatly helpful. But you must make sure that you do not become sufficient in just the use of counselors, but instead truly become sufficient in God's love for you, and your love for God. I urge you today- don't misuse your Jehoiadas. Learn also to depend on God yourself.