I always wondered, why Gita contains 1st chapter, which doesn't have much of sermons unlike other chapters!
Or for that matter why Gita doesn't start with Krishna commencing on divine teachings?
Swami Chinmayananda in The Holy Geeta explains the relevance of the first chapter of Gītā.
For the reader to gain a much fuller understanding of the Gītā, Chinmayananda says, having the same mental attitude as Arjuna is a prerequisite.
This chapter is called by a self-contradicting title. It is named as the "Yoga of ARJUNA'S GRIEF". If 'grief' could be Yoga, almost all of us, without a choice, are already Yogins.
In the commentary of this chapter, I indicated that the Arjuna-condition of utter despair is the auspicious mental attitude wherein the Geeta-seeds are to be sown, and the flowers of Krishna-perfection gathered. Be it in an individual or a society, in a community or a nation, religion and philosophy will be in demand only when the heart has come to experience the Arjuna-grief.
To the extent that the world of today has felt its incompetence to face the battle of life, not daring to destroy their near and dear values of economic expansion and industrial lust, to that extent it is fit for listening to the message of the Geeta. Just as the act of cooking, by itself, is not fulfilled without the eating that follows, so also, in spite of the best that may be available in life, a sense of incompleteness is felt and a deep hunger to gain a better awareness and a fuller existence in the world is experienced.
The scriptural texts cannot, in themselves, help any one. Since this mental condition is so unavoidable before the actual Yoga is started, even the initial mental condition is called by a wishful anticipation, as Yoga. For learning and living the Geeta, the Arjuna-condition is the initial sadhana.