The Yoga Sutras of Patanjali is the definitive text in yoga. This ancient text was written in India over 4,000 years ago and is the basis of many forms of yoga, including raja, Ashtanga and hatha. The original text is available with translations and interpretations by many authors, including well known yoga masters, such as BKS Iyengar, Swami Satchidananada and many others.
Because the interpretations vary, some people choose to read a few different variations to get an idea of the different philosophies. BKS Iyengar is one of the most respected yoga masters in the world and is the author of numerous books on yoga, including Light on the Yoga Sutras of Patanjali.
Light on the Yoga Sutras of Patanjali is not a book of asanas. Although asana is one of the eight limbs, the information is still more theory than practice. Each of the eight limbs is described fully and Iyengar ties them all together to describe the whole philosophy of the practice.
This book is a good choice for an easy to understand interpretation of the yoga sutras. The commentary and concepts are clearly explained in language that is easy to understand. Iyengar translates each of the yoga sutras and provides a thorough discussion of the meaning of the text.
This is a good reference book for anyone studying the spiritual aspects of yoga or following the eight limbed path of yoga, as described in the Yoga Sutras. Iyengar provides a variety of material in the book, including charts and graphs, glossary, index and a wealth of other information.
Although Iyengar does address the spiritual aspects of yoga throughout the book, the idea of God is general enough to fit with any religion. People of all faiths practice yoga and their own religion without conflict and this book fits that concept. You can take or leave and interpret the information as you want.