Cc. Madhya 6.80

śiṣya-gaṇa kahe,—'īśvara kaha kon pramāṇe'
ācārya kahe,—'vijña-mata īśvara-lakṣaṇe'

śiṣya-gaṇa kahe—the disciples of Sārvabhauma Bhaṭṭācārya said; īśvara kaha—you say the Supreme Personality of Godhead; kon pramāṇe—by what evidence; ācārya kahe—Gopīnātha Ācārya replied; vijña-mata—statements of authorized persons; īśvara-lakṣaṇe—in understanding the Supreme Personality of Godhead.

The disciples of Sārvabhauma Bhaṭṭācārya retaliated, “By what evidence do you conclude that Śrī Caitanya Mahāprabhu is the Supreme Lord?” Gopīnātha Ācārya replied, “The statements of authorized ācāryas who understand the Supreme Personality of Godhead are proof.”

Since the appearance of Śrī Caitanya Mahāprabhu, there have been many pseudo incarnations in India who do not present authorized evidence. Five hundred years ago the disciples of Sārvabhauma Bhaṭṭācārya, being very learned scholars, were certainly right in asking Gopīnātha Ācārya for evidence. If a person proposes that he himself is God or that someone else is an incarnation of God or God Himself, he must cite evidence from śāstra to prove his claim. Thus the request of the Bhaṭṭācārya's disciples is quite bona fide. Unfortunately, at the present moment it has become fashionable to present someone as an incarnation of God without referring to the śāstras. Before an intelligent person accepts someone as an incarnation of God, however, he must ask about the evidence. When the disciples of Sārvabhauma Bhaṭṭācārya challenged Gopīnātha Ācārya, he immediately replied correctly: “We must hear the statements of great personalities in order to understand the Supreme Personality of Godhead.” Lord Kṛṣṇa is established as the Supreme Personality of Godhead by statements from authorized persons like Brahmā, Nārada, Vyāsadeva, Asita, Arjuna and many others. Similarly, Śrī Caitanya Mahāprabhu is also established as the Supreme Personality of Godhead by evidence from the same personalities. This will be explained later.