Kṛṣṇa is original spiritual master. Tene brahma hṛdā ādi-kavaye (SB 1.1.1). Kṛṣṇa first instructed Brahmā, Ādi-kavi. From Brahmā we have got these Vedas, Vedic knowledge. Therefore, Kṛṣṇa is the original spiritual master. Aham evāsam agre. Before creation, Kṛṣṇa was there. Aham ādir hi devānām (BG 10.2). Kṛṣṇa is the origin of all the devas. Devas means Brahmā, Viṣṇu, Maheśvara, then all other demigods. So in this way, Kṛṣṇa is the original spiritual master, just like He's the spiritual master of Arjuna.
So study of Bhagavad-gītā means if you follow the footprints of Arjuna, then you are also as good as Arjuna. Not as good; I mean to say that your knowledge is perfect. Perfect in this sense, that Arjuna accepted Kṛṣṇa as Paraṁ Brahman; you accept Kṛṣṇa as Paraṁ Brahman; then your study of Bhagavad-gītā is perfect. And if you make your so-called erudite scholarship, commentary, "It is not to Kṛṣṇa," then you are spoiled. Your life is spoiled, your study is spoiled. Sādhu-mārga-anugamanam.
So if you want to study Bhagavad-gītā, you follow what Arjuna says. Where is the difficulty? What Arjuna has said about Kṛṣṇa, that is already there in the Bhagavad-gītā. Arjuna said, paraṁ brahma paraṁ dhāma pavitraṁ paramaṁ bhavān, śāṣvataṁ puruṣam ādi (BG 10.12). You accept Him, Kṛṣṇa. Why do you try to make minus Kṛṣṇa Bhagavad-gītā? This is rascaldom. That is not study of Bhagavad-gītā. Bhagavad-gītā as it is. Study Bhagavad-gītā as it is; then you'll be benefited.