Q: Why Lord Krishna didn’t teach the Gita to Duryodhana instead of Arjuna ? Because that would have avoided the War and there would have been no killing?
Rajini Ma: Krishna is the innermost core in us, the atma tatwa! Arjuna is the egotistic personality. The divine element in us gets activated only when the ego surrenders fully.
Only when Arjuna laid down the Gandhiva, his weapon, and goes down on his knees and surrenders fully to the Divine realizing the total inability and futility of whatever, he the Egotist has learnt and achieved. The very realization that all that he as Ego has learnt, studied, acquired and achieved are of no use to him, in fact absolutely no use to him at all. Only then does he surrender to the Divine and only when this total surrendering happens, does the Divine start flowing through the hollow and empty instrument of the body which is devoid of the ego.
As the Ego surrendered in Arjuna , the inner divine of Arjuna became activated and the Divine Music of the Baghawat Gita happened!!!
Surely now your immediate question is answered.