Prabhupāda: Just like Arjuna, fighting. Fighting, if you take..., just like nowadays fighting is going on, that is material. But the same fighting done for Kṛṣṇa is spiritual.
Dr. Singh: It is the attitude with which one does it.
Prabhupāda: Yes. That is the definition of bhakti. Bhakti means hṛṣīkeṇa hṛṣīkeśa-sevanaṁ bhaktir ucyate (CC Madhya 19.170). Hṛṣīkeṇa hṛṣīkeśa-sevanaṁ, that is bhakti. Now to serve Kṛṣṇa, Hṛṣīkeśa, that requires qualification. Just like you are king, if somebody wants to serve you as your secretary, he has to have specific qualifications. Not ordinary man. Similarly, bhakti means to serve Kṛṣṇa. So everyone can serve Kṛṣṇa provided he is qualified. And what is that qualification?
Dr. Singh: Love of Kṛṣṇa.
Prabhupāda: Yes.