Generally, we work for our sense gratification: "I have got this money. I must use for my sense gratification or for my relative's sense gratification or for my country's sense gratification, for my society's sense gratification." So this is materialism. But when the same thing is turned for Kṛṣṇa's sense gratification, that is spiritual.
That is the difference between prema and kāma. Kāma. It has been very simplified by Kavirāja Kṛṣṇadāsa Gosvāmī in his Caitanya-caritāmṛta: ātmendriya-prīti-vāñchā karanam 'kāma' (CC Adi 4.165). Ātmendriya-prīti. If you want to satisfy your senses, that is called kāma, lust. Kṛṣṇendriya-prīti-vāñchā dhare 'prema' nāma. The same thing, when you try to satisfy the senses of Kṛṣṇa, that is called prema.
So we have to divert the activities for Kṛṣṇa. That is Kṛṣṇa consciousness. Just like Arjuna. Arjuna, he, in the beginning, he denied to fight. That, our subject matter. He was crying. "No, no, I cannot fight." So apparently Arjuna was very nice gentleman that he is forgetting his claim over the kingdom, he's nonviolent, he's not willing to fight with his brothers, and he was crying so compassionate. So from materialistic point of view, he was very nice. But immediately, as we'll begin tomorrow, Kṛṣṇa says that, "Why you are thinking like anārya?" Anārya. Anārya-juṣṭam. "This kind of thinking is not for āryas, Āryans. It is for the non-Āryans." He did not . . .
And the whole Bhagavad-gītā was spoken to Arjuna to make him ārya. And at the end, Kṛṣṇa inquired from Arjuna that "What is your decision?" Yathecchasi tathā kuru (BG 18.63) But Arjuna replied, kariṣye tad-vacanam. Kariṣye vacanaṁ (BG 18.73): "Now I shall fight."
And Kṛṣṇa gave him certificate, bhakto 'si priyo 'si me (BG 4.3): "You are very dear friend, and My great devotee." Now, fighting is not very good business, killing. But sometimes, by killing, one can become a great devotee of Kṛṣṇa. He was a warrior, fighter. His business was to fight, but he fought for Kṛṣṇa. Then he became a devotee. That is sva-karmaṇā tam abhyarcya (BG 18.46). He . . . Arjuna, brāhmin and kṣatriya.