The word yugānurūpābhyām is significant here. Anurūpa means “suitable” or “appropriate.” The Supreme Personality of Godhead, Kṛṣṇa, anxiously desires that all conditioned living entities come back home, back to Godhead, for an eternal life of bliss and knowledge. Thus, the Lord reveals Himself in each of the four ages — Satya, Tretā, Dvāpara and Kali — in a form appropriate for worship by the human beings of that age. In his Laghu-bhāgavatāmṛta (Pūrva-khaṇḍa 1.25), Śrīla Rūpa Gosvāmī states:

kathyate varṇa-nāmābhyāṁ
 śuklaḥ satya-yuge hariḥ
raktaḥ śyāmaḥ kramāt kṛṣṇas
 tretāyāṁ dvāpare kalau

“The Supreme Lord Hari is described in terms of His color and names as śukla [white, or the most pure] in Satya-yuga, and as red, dark blue and black respectively in Tretā, Dvāpara and Kali.” Thus, although in each age various names suitable for glorifying the Lord are given, such as Haṁsa and Suparṇa in Satya-yuga, Viṣṇu and Yajña in Tretā-yuga, and Vāsudeva and Saṅkarṣaṇa in Dvāpara-yuga, similar names are not given for Kali-yuga, although such names exist, in order to avoid disclosing cheaply the truth of the incarnation of Śrī Caitanya Mahāprabhu.

In Kali-yuga human society is infested with hypocrisy and superficiality. There is a strong tendency toward imitation and fraud in this age. Therefore the incarnation of Śrī Caitanya Mahāprabhu is revealed in Vedic literature in a confidential, discrete way, so that it will be known to the authorized persons who can then propagate the mission of the Lord on the earth. We actually see in this modern age that many foolish and ordinary persons claim to be God or incarnations, avatāras, etc. There are many cheap philosophies and academies that promise, for a moderate fee, to make one God in a short time. In America one famous religious group promises its followers that they will all become the Supreme Lord in heaven. Such bogus preaching goes on in the name of Christianity. Thus, were Caitanya Mahāprabhu’s name widely spoken of in Vedic literature, there would soon be a veritable plague of imitation Caitanya Mahāprabhus infesting the world.

Therefore, to prevent this pandemonium, discretion is exercised in the Vedic literatures in Kali-yuga, and in a sober, concealed way the actual followers of Vedic culture are informed through the Vedic mantras of the descent of Śrī Caitanya Mahāprabhu. This discrete system, selected by the Lord Himself for His appearance in Kali-yuga, is proving to be greatly successful on the earth planet. And throughout the world millions of people are chanting the holy names of Kṛṣṇa without the unbearable harassment of hundreds and thousands of imitation Caitanya Mahāprabhus. Those who seriously desire to approach the Supreme Personality of Godhead can easily understand the Lord’s mission, whereas cynical materialistic rascals, puffed up by false prestige and madly considering their insignificant intelligence to be greater than the intelligence of Lord Kṛṣṇa, cannot understand the beautiful arrangements made by the Lord for His graceful descent into the material world. Thus, although Kṛṣṇa is śreyasām īśvaraḥ, or the Lord of all benedictions, such foolish persons turn away from the Lord’s mission and in this way deprive themselves of their own true benefit in life.