Q. Why krishna wanted Arjuna to fight the Mahabharat war? What was the aim behind this fighting?
Q. One of the purpose of coming for Krishna into this world is to establish religion(yada yada hi dharmasya…..). So the aim of this war was to remove the irreligious people.
Srila Prabhupada writes in Bhagavad gita 1.1 purport…..
Both the Pandavas and the sons of Dhritrashtra belong to the same family but Dhritrashtra’s mind is disclosed herein. He deliberately claimed only his sons as Kurus and he separated the sons of Pandu from the family heritage. One can thus understand the specific position of Dhritrashtra in his relationship with his nephews, the sons of Pandu. As in the paddy field the unnecessary plants are taken out, so it is expected from the very beginning of these topics that in the religious field of Kurushetra, where the father of religion, Shri Krishna, was present, the unwanted plants like Dhritrashtra’s son Duryodhana and others would be wiped out and the thoroughly religious persons headed by Yudhishtra would be established by the Lord.
Krishna would have killed everyone Himself. As He showed, everybody was going in to His Universal form. But Krishna loves to give credit to His devotees and that is the reason, He engaged Arjuna….(nimitta matra bhava savyasachi……….) in this fight, so that whole world can glorify Arjuna.