Just like Arjuna was thinking in the beginning that "Fighting and killing is not good, especially fighting with the family members and killing them. No, no, I cannot do that. Bad work." He was thinking it was bad. But same thing he did. When he understood Bhagavad-gītā, he did not do anything else, because he was a fighter, he was a warrior. In the beginning he was refusing because he was trying to satisfy his senses, "Oh, it is very good. I think it is . . . I think . . ." What you are? You are always misguided if you think like that. But the same Arjuna, when understood Bhagavad-gītā . . . Kṛṣṇa inquired from him, "Now what is your decision?" Now, kariṣye vacanaṁ tava (BG 18.73). "Yes, now I have decided." So what is that vacanaṁ tava? Kṛṣṇa asked him to fight. So same fighting, how he became good now? Because Kṛṣṇa wanted it. A good work.
So this should be our motto of life, that you should act if Kṛṣṇa is pleased. This is good work. That is confirmed in many places in Śrīmad-Bhāgavatam. Ataḥ pumbhir dvija-śreṣṭhāḥ (SB 1.2.13), Sūta Gosvāmī said in the meeting of great learned scholars and brāhmaṇas in Naimiṣāraṇya. He said, dvija-śreṣṭhāḥ: "O best of the brāhmaṇas who have assembled here to hear me." Dvija-śreṣṭhāḥ. Ataḥ pumbhir dvija-śreṣṭhā varṇāśrama-vibhāgaśaḥ (SB 1.2.13). Again that varṇāśrama. Without varṇāśrama, it is a rascal society, that's all. It is not even human society. It is animal society. But that we have lost now. Again it is said, varṇāśrama-vibhāgaśaḥ. Ataḥ pumbhir dvija-śreṣṭhāḥ. He was speaking amongst the very learned scholars and brāhmaṇas. Therefore he addressed, "My dear all great brāhmaṇas, dvija-śreṣṭhā." Dvija means brāhmaṇa, kṣatriya, vaiśya. And the brāhmaṇa is the śreṣṭha, the best of the dvijas. Dvija means twice-born—one birth by the father and mother, and the next birth through the guru and Vedic knowledge. Vedic knowledge is the mother and guru is the father. The next birth. That is called dvija, twice-born. Once born by father and mother, that is śūdra. Janmanā jāyate śūdraḥ. First birth is śūdra. The next birth, when he is trained up by the guru in Vedic knowledge, that is real birth. Therefore all of them were first-class brāhmaṇas, dvija, with saṁskāra. Therefore they are addressed dvija-śreṣṭhāḥ. Ataḥ pumbhir dvija-śreṣṭhā varṇāśrama-vibhāgaśaḥ. Again this varṇāśrama.