In the absolute sense there is no duality. If I speak something, because I am not speaking in the absolute, therefore my speaking and my self, different. But here I am speaking the words of Lord Kṛṣṇa. Therefore the words of Lord Kṛṣṇa is not different from Kṛṣṇa. So if we think of Bhagavad-gītā, the instructions which we receive from Bhagavad-gītā, that is also thinking of Kṛṣṇa.
So ananyāś cintayanto mām: "Always who are thinking about Me . . ." ye janāḥ paryupāsate. And why one should think of Kṛṣṇa unless he has fully surrendered to Kṛṣṇa? Unless one has taken the business of Kṛṣṇa, he cannot think of Kṛṣṇa. He cannot think of Kṛṣṇa. Therefore it is said that ananyāś cintayanto māṁ ye janāḥ paryupāsate. Paryupāsate means constantly worshiping in that way. Teṣāṁ nityābhiyuktānām. Abhiyukta: he is always engaged in Kṛṣṇa consciousness.
Therefore, yoga-kṣemaṁ vahāmy aham. Not that only the materialistic people will remain happy. Kṛṣṇa assures that one who is always engaged in Kṛṣṇa consciousness, his happiness will be not devolved. "He will be also happy because I will make him, I will supply him whatever he requires."
It is very easy to understand. Just like somebody maintains his family, children. He all day works, and he has the aim, how his family member will be happy, because he knows that those people, those children, they are fully dependent upon him. This is same consciousness. Because wherefrom this consciousness comes unless it is not in Kṛṣṇa? Janmādy asya yataḥ (SB 1.1.1). In the Vedānta-sūtra it is stated, whatever you think, whatever you see, it has its origin. And where is that origin? In Kṛṣṇa.