Here’s a well-structured blog post on one of the most popular verses of the Bhagavad Gita—Chapter 2, Verse 47 (Karmanye Vadhikaraste).

अपनी सफलता और अपने विकास के उपकरण हम बाहर की दुनिया में खोजते फिरते हैं लेकिन यह भूल जाते हैं कि उसकी सबसे बड़ी चाबी तो हमारे अंदर ही छिपी हुई है। यह चाबी है आत्म जागरूकता।

Hindu's have a caste system which is only of its kind in the world. A 'caste' is a community to which entry is based on birth in that community. Hindu society is divided into hundreds of castes. Marriages used to take place earlier only within the members of the same caste. The different castes where arranged hierachically, with some being called "higher castes" and some being called "lower castes" in terms of social status. This system has been broken quite a bit during the last 100 years, yet it continues in some form or the other. Most traditional Hindu scriptures and Hindu scholars justify the birth based caste system. The big question is whether the Bhagavad Gita also supports this system?