In the conclusion he said that ete cāṁśa-kalāḥ puṁsaḥ kṛṣṇas tu bhagavān svayam (SB 1.3.28), that "All the descriptions that are given of different incarnations, they are partially or part of the partial representation of God, but this Kṛṣṇa whom I have mentioned, He is the Supreme Personality of Godhead Himself." He is not part. Cent percent. Cent percent God.
So there is evidence of authority. And practically, if we believe the śāstras, the scriptures, authorities, then see who can be more powerful than Kṛṣṇa, who can be more beautiful than Kṛṣṇa, who can be more famous than Kṛṣṇa? Just like Kṛṣṇa appeared five thousand years before, but His knowledge, which He gave us in the shape of Śrīmad Bhagavad-gītā, still it is worshiped. It is worshiped not only by the Hindus or the Indians, but this Bhagavad-gītā is read all over the world. In your country there are at least fifty kinds of different editions of Śrīmad-Bhāgavatam (Bhagavad-gītā) written by different American thoughtful men. Similarly you'll find in England, in Germany, in France, in, I mean to say, all other countries you'll find hundreds of editions of Bhagavad-gītā. Just see who can be more famous and who can be more wise than Kṛṣṇa? There are many other evidences if we believe śāstra. That Kṛṣṇa married 16,108 wives, and He provided each one of them with big palaces and each one of them had ten children, and from ten children there were many other children also.
So these are the evidences from revealed scripture. And in the Brahma-saṁhitā also, Kṛṣṇa is accepted as the Supreme Personality of Godhead. This is a very old book, supposed to be written by Brahma. It is called Brahma-saṁhitā. In that Brahma-saṁhitā it is said that īśvaraḥ paramaḥ kṛṣṇaḥ (Bs. 5.1). Īśvaraḥ means God. There are many gods, but... In Sanskrit language, about God, there are many demigods, and there is Supreme God. So this Brahma-saṁhitā says, īśvaraḥ paramaḥ kṛṣṇaḥ, "Kṛṣṇa is the Supreme God. He is the God of gods." Īśvaraḥ paramaḥ kṛṣṇaḥ sac-cid-ānanda-vigrahaḥ (Bs. 5.1).