"If you’re not tested, you take teaching after teaching and think you’re OK, but when you’re confronted with a difficult situation, it’s possible that you’ll find you’re not OK at all. So that’s why true Dharma practitioners welcome trouble. It gives them a chance to see if what they’ve been studying works or not, a chance to transform suffering into happiness. Otherwise you just go blithely along, completely out of touch with reality, thinking you’re OK when you’re not, because you haven’t actually been practicing Dharma at all.
To put this another way, painful situations are a source of wisdom. How so? First of all, painful situations arise as a result of nonvirtuous karma. When we experience pain we should ask why is this happening to me? How has this come about? That sort of inquiry leads us to understand that it’s the ripening of negative karma we created in the past. That basic understanding can grow into wisdom; the painful experience helps us develop a deeper understanding that is beyond the merely intellectual.
Of course, if you’re completely ignorant, it doesn’t matter how much suffering you experience, there’s no way for that to lead to happiness. All you do is go from misery to more misery. If, on the other hand, you have at least a modicum of Dharma wisdom, when you’re in difficulty you know how to use that experience to lead yourself into happiness."