Can we ever differentiate between different fingers in the hand? All the fingers had a different role to play. We just could not lay importance or single out one from the rest. From spirituality point of view all 700 shlokas verses contained in Bhagavad Gita had an independent story to tell. The purport of each and every shloka verse of Bhagavad Gita is different.
On path of spirituality we had to follow all the 700 shlokas verses to reach cosmic end of life, state of enlightenment. We just could not pick a select few; it would never serve the purpose.
The story of five blind men with an elephant says it all. The one who felt the leg of the elephant stated elephant was like a pole. If we indulged in only a few shlokas verses then our fate also would be the same. To see the whole picture we have to indulge in all the 700 shlokas verses.
Some shlokas verses dealt with karma yoga, others with jnana yoga; some with bhakti yoga. There were innumerous precepts in the field of spirituality that helped one kill queries within. All the queries within had to be demolished forever, rather dissolved.
The only purport of all 700 shlokas verses of Bhagavad Gita was dissolving our queries within one by one. The moment all queries within dissolved forever, one gained enlightenment that very moment. This state is called Nirvikalpa Samadhi (when not a single thought entered our brain uninvoked).
Indulgence in Bhagavad Gita should be for only one purpose, liberation from cycle of birth and death forever. And for that every single shloka verse had to be contemplated upon. Contemplation (chintan) is the path how we indulged in shlokas verses of Bhagavad Gita. Literally we could never understand the purport of all shlokas verses in Bhagavad Gita.
The moment we mastered the art of contemplation (chintan), our spiritual journey extradited manifold. Before indulgence in Bhagavad Gita we must learn the right way to contemplate. Most human beings world over failed on this count. Prime reason why in last 150 years amongst 7 billion people existing world over only two spiritual stalwarts succeeded in liberating self from cycle of birth and death forever, Sri Ramakrishna Paramhansa and Maharshi Ramana.
Master art of contemplation truly is not that easy! We had to become a Swami Vivekananda to do that.