The appearance of Kṛṣṇa is the answer to all imaginative iconography of the Supreme Personality of Godhead. Everyone imagines the form of the Supreme Personality of Godhead according to his mode of material nature. In the Brahma-saṁhitā it is said that the Lord is the oldest person. Therefore a section of religionists imagine that God must be very old, and therefore they depict a form of the Lord like a very old man. But in the same Brahma-saṁhitā, that is contradicted: although He is the oldest of all living entities, He has His eternal form as a fresh youth. The exact words used in this connection in Śrīmad-Bhāgavatam are vijñānam ajñāna-bhidāpamārjanam. Vijñānam means transcendental knowledge of the Supreme Personality of Godhead. Vijñānam is also experienced knowledge. Transcendental knowledge has to be accepted by the descending process of disciplic succession, as Brahmā presents the knowledge of Kṛṣṇa in the Brahma-saṁhitā. The Brahma-saṁhitā is vijñānam as realized by Brahmā’s transcendental experience, and in that way he presented the form and the pastimes of Kṛṣṇa in the transcendental abode. This knowledge is ajñāna-bhidāpamārjanam, that which can smash all kinds of speculation in ignorance. People are imagining the form of the Lord: sometimes He has no form and sometimes He has form, according to their different imaginations. But the presentation of Kṛṣṇa in the Brahma-saṁhitā is vijñānam—scientific, experienced knowledge given by Lord Brahmā and accepted by Lord Caitanya. There is no doubt about it. Kṛṣṇa’s form, Kṛṣṇa’s flute, Kṛṣṇa’s color—everything is reality. Here it is said that this vijñānam is always defeating all kinds of speculative knowledge. “Therefore, without Your appearing as Kṛṣṇa, as You are, neither ajñāna-bhidāpamārjanam (destruction of the nescience of speculative knowledge) nor vijñānam would be realized. In other words, Your appearance will vanquish the ignorance of speculative knowledge and establish the real experienced knowledge of authorities like Lord Brahmā. Men influenced by the three modes of material nature imagine their own God according to the modes of material nature. In this way God is presented in various ways, but Your appearance will establish what the real form of God is.”
The highest blunder committed by the impersonalists is to think that when the incarnation of God comes He accepts the form of matter in the mode of goodness. Actually, the form of Kṛṣṇa or Nārāyaṇa is transcendental to any material idea. Even the greatest impersonalist, Śaṅkarācārya, has admitted, nārāyaṇaḥ paro ’vyaktāt: the material creation is caused by the avyakta (impersonal) manifestation of matter, or the nonphenomenal total reservoir of matter, but Kṛṣṇa is transcendental to that material conception. That is expressed in Śrīmad-Bhāgavatam as śuddha-sattva, or transcendental goodness. He does not belong to the material mode of goodness, and He is above the position of material goodness. He belongs to the transcendental, eternal status of bliss and knowledge.
“Dear Lord, when You appear in Your different incarnations, You take different names and forms according to different situations. Lord Kṛṣṇa is Your name because You are all-attractive; You are called Śyāmasundara because of Your transcendental beauty. Śyāma means ‘blackish,’ yet it is said that You are more beautiful than thousands of Cupids (kandarpa-koṭi-kamanīya). Although You appear in a color which is compared to the blackish cloud, because You are the Transcendental Absolute, Your beauty is many, many times more attractive than the delicate body of Cupid. Sometimes You are called Giridhārī because You lifted the hill known as Govardhana. You are sometimes called Nandanandana or Vāsudeva or Devakīnandana because You appear as the son of Mahārāja Nanda or Vasudeva or Devakī. Impersonalists think that Your many names or forms are given according to a particular type of work and quality because they accept You from the position of a material observer.