Shrimad Bhagwad Gita is one of the most holy books in Sanatan Dharm (Hinduism). The Gita contains the sum of all the knowledge from Ved and Upanishad and Puran and Ramayan and Mahabharat. The sloks in Gita have to be studied and explained by a Guru who has proper knowledge in scriptures and God. One cannot just read the sloks and say I understand the Gita. It is complex as rocket science if not more. The best commentary written on Bhagavad Gita is by Swami Ramsukhdas. You can order the 2000 page book from Gita press (www.gitapress.org).