As the Lord appeared just to maintain Lord Brahmā from the attack of Madhu and Kaiṭabha, He also appeared to protect the great devotee Prahlāda Mahārāja. Similarly, Lord Caitanya appeared in order to protect the fallen souls of Kali-yuga. There are four yugas, or millenniums — Satya, Tretā, Dvāpara and Kali. In all the yugas but Kali-yuga, the Lord appears in various incarnations and asserts Himself as the Supreme Personality of Godhead, but although Lord Śrī Caitanya Mahāprabhu, who appears in Kali-yuga, is the Supreme Personality of Godhead, He never asserted Himself as such. On the contrary, whenever Śrī Caitanya Mahāprabhu was addressed as being as good as Kṛṣṇa, He blocked His ears with His hands, denying His identity with Kṛṣṇa, because He was playing the part of a devotee. Lord Caitanya knew that in Kali-yuga there would be many bogus incarnations pretending to be God, and therefore He avoided asserting Himself as the Supreme Personality of Godhead. Lord Caitanya Mahāprabhu is accepted as the Supreme Personality of Godhead, however, in many Vedic literatures, especially in Śrīmad-Bhāgavatam (11.5.32) :

kṛṣṇa-varṇaṁ tviṣākṛṣṇaṁ sāṅgopāṅgāstra-pārṣadam yajṣaiḥ saṅkīrtana-prāyair yajanti hi sumedhasaḥ

In Kali-yuga, intelligent men worship the Supreme Personality of Godhead in the form of Śrī Caitanya Mahāprabhu, who is always accompanied by His associates such as Nityānanda, Advaita, Gadādhara and Śrīvāsa. The entire Kṛṣṇa consciousness movement is based on the principles of the saṅkīrtana movement inaugurated by Śrī Caitanya Mahāprabhu. Therefore one who tries to understand the Supreme Personality of Godhead through the medium of the saṅkīrtana movement knows everything perfectly. He is sumedhas, a person with substantial intelligence.