Know why you should be grateful for adversity?

About the video:

When you have come up against adversity and go to an experienced practitioner for guidance, they will say “Congratulations you have something to chant about.” Why would they say this? They know that no one is out to get you, that adversity is a normal part of the path to enlightenment. As the wisdom of the Lotus Sutra vol V1. P. 88 says,
“The benefit we receive when we initially take faith is like a small mountain. The boundless life force of    Buddhahood is...