See 2 Chronicles 24.
v2
And Joash did [that which was] right in the sight of the LORD all the days of Jehoiada the priest.
It's easy to do what's right when there's a Jehoiada in our lives. We just follow his example, and, as long as he's around, and being a good example, we do what's right. But what about when that good example isn't around any more?
Joash's problem is that he didn't remember. He disregarded all of the kindness that Jehoiada had done for him (which was a lot,) and became very wicked. Do we remember our Jehoiadas? After they're not around, or after they're not a good example any more, do we forget, and stop doing what's right, but be very wicked, instead?
What we can see from this chapter, is that God is real, and when people changed, He didn't. We should remember to do what's right, even when other people who have been our examples, change.