Iyengar: "Health is religious."

I bought this book in India four years ago and just recently started reading it: The Tree of Yoga by BKS Iyengar.

Here's an excerpt that caught my attention: 

“Each one has to train himself or herself, for without discipline we cannot become free, nor can there be freedom in the world without discipline. Discipline alone brings true freedom. If you have to gain health, do you think you can do so without discipline? Moderation in living is essential. This is why yoga starts with a code of conduct which each individual has to develop. One who is undisciplined is an irreligious person. One who is disciplined is a religious person. Health is religious. Ill-health is irreligious.”