Duṣkṛtinaḥ means one who has got merit, but the merit is being engaged for sinful activities. Just like the atomic bomb. One who has manufactured this, he has got merit, certainly, great scientist. But how he has used his merit? To kill men, that's all. "So men are being killed, sir. They are already dying. What you have manufactured?" But, "No, I have got Nobel Prize." "Why?" "I have invented something which will very quickly kill." That's all. Not slowly, but quickly. And he is offered Nobel Prize. You see? He has manufactured something. "Why don't you manufacture something that men will not die? Then I could consider your merit." But no; his merit is utilized for doing something sinful. That is called duṣkṛtinaḥ. These classes of men, they cannot surrender to Kṛṣṇa, because they have to suffer for their sinful activities. So they cannot surrender.
Surrender means you become freed from all sinful activities.
Ahaṁ tvāṁ sarva-pāpebhyo mokṣayiṣyāmi (BG 18.66). Kṛṣṇa assures, "If you surrender, then I immediately give you release from all reaction of sinful life." But they will not surrender. Therefore they will continue; they will suffer. Na māṁ duṣkṛtino mūḍhāḥ. So mūḍhā means rascal, fool. Kṛṣṇa is giving so much opportunity, but he will not accept. Therefore mūḍhā. And narādhamāḥ. Narādhamāḥ, lowest of the mankind. This instruction can be taken in this human form of life. Kṛṣṇa says: "Surrender unto Me." A dog cannot do that, but a human being can do it. If he does not do it, then he's the lowest of the mankind. He is not taking the opportunity. Narādhamāḥ. But one may say that there are so many big, big men, educated, learned. Kṛṣṇa says, māyayāpahṛta-jñānā. Although they have learned so many knowledge, still, māyā has taken. The real knowledge has been taken. Āsuraṁ bhāvam āśritāḥ. Because they are demons and atheists, they cannot take it.
So what can be done? Kṛṣṇa is offering all opportunities, and we, humble servant of Kṛṣṇa, we are trying to preach it. But the rascals will not accept it. What can be done? That is the difficulty. They want to continue to remain as rascals. That is. What can be done? This is the difficulty. Otherwise everything is there. If we take it . . . even a child can take benefit out of it, of Kṛṣṇa consciousness. That you have seen practically. But we will not take it.