Hare Kṛṣṇa,
The confidential purposes behind the Lord’s appearance as Śrī Caitanya Mahāprabhu reveal ever-deepening layers of transcendental intent. Thus far, we understand that Śrī Kṛṣṇa descended to taste the unparalleled bliss experienced by Śrīmatī Rādhārāṇī. Yet the revelation becomes still more confidential. The Lord did not merely wish to relish the conjugal mellow (mādhurya-rasa), but specifically the supreme sweetness of love in the paramour relationship (parakīya-bhāva), which reaches its fullest and most exalted expression in Vraja.
“Svakīya is the relationship with Kṛṣṇa as a formally married husband, and parakīya is the relationship with Kṛṣṇa as a paramour. Expert analysts have decided that the transcendental ecstasy of the parakīya mellow is better because it is more enthusiastic. This phase of conjugal love is found in those who have surrendered to the Lord in intense love, knowing well that such illicit love with a paramour is not morally approved in society. The risks involved in such love of Godhead make this emotion superior to the relationship in which such risk is not involved. The validity of such risk, however, is possible only in the transcendental realm. Svakīya and parakīya conjugal love of Godhead have no existence in the material world, and parakīya is not exhibited anywhere in Vaikuṇṭha, but only in the portion of Goloka Vṛndāvana known as Vraja.” (CC Adi 4.50 Purport)
Śrī Kṛṣṇa not only desired to taste this supreme sweetness Himself, but also mercifully wished that the living entities—especially sincere devotees still situated in the material world—might receive a glimpse of this otherwise inaccessible realm of divine love.
“ It is further stated here in Caitanya-caritāmṛta that the parakīya sentiment exists only in that transcendental realm and nowhere else. This highest form of ecstasy can exist only in the most confidential part of the transcendental world, but by the causeless mercy of the Lord we can have a peep into that invisible Vraja.” (CC Adi 4.50 Purport)
“The transcendental mellow relished by the gopīs in Vraja is superexcellently featured in Śrīmatī Rādhārāṇī. Mature assimilation of the transcendental humor of conjugal love is represented by Śrīmatī Rādhārāṇī, whose feelings are incomprehensible even to the Lord Himself. The intensity of Her loving service is the highest form of ecstasy. No one can surpass Śrīmatī Rādhārāṇī in relishing the transcendental mellow qualities of the Lord. Therefore the Lord Himself agreed to assume the position of Rādhārāṇī in the form of Lord Śrī Gaurāṅga. He then relished the highest position of parakīya-rasa, as exhibited in the transcendental abode of Vraja.” (CC Adi 4.50 Purport)
Thus, Srila Rupa Goswami glorifies Sri Caitanya Mahaprabhu with glorious prayers:
CC Adi 4.51: “Lord Caitanya is the shelter of the demigods, the goal of the Upaniṣads, the be-all and end-all of the great sages, the beautiful shelter of His devotees, and the essence of the love of the lotus-eyed gopīs. Will He again be the object of my vision?
CC Adi 4.52: “Lord Kṛṣṇa desired to taste the limitless nectarean mellows of the love of one of His multitude of loving damsels [Śrī Rādhā], and so He has assumed the form of Lord Caitanya. He has tasted that love while hiding His own dark complexion with Her effulgent yellow color. May that Lord Caitanya confer upon us His grace.”
CC Adi 4.55: “The loving affairs of Śrī Rādhā and Kṛṣṇa are transcendental manifestations of the Lord’s internal pleasure-giving potency. Although Rādhā and Kṛṣṇa are one in Their identity, They separated Themselves eternally. Now these two transcendental identities have again united, in the form of Śrī Kṛṣṇa Caitanya. I bow down to Him, who has manifested Himself with the sentiment and complexion of Śrīmatī Rādhārāṇī although He is Kṛṣṇa Himself.”
Lord Caitanya Mahāprabhu personally approaches the fallen conditioned souls of the iron age to deliver the highest principle of transcendental relationships with the Lord. The activities of Lord Caitanya are primarily in the role of the pleasure-giving portion of His internal potency.
Who is His pleasure-giving potency?
“In fact, Rādhārāṇī is the internal potency of Śrī Kṛṣṇa, and She eternally intensifies the pleasure of Śrī Kṛṣṇa. Impersonalists cannot understand this without the help of a mahā-bhāgavata devotee. The very name Rādhā suggests that She is eternally the topmost mistress of the comforts of Śrī Kṛṣṇa. As such, She is the medium transmitting the living entities’ service to Śrī Kṛṣṇa. Devotees in Vṛndāvana therefore seek the mercy of Śrīmatī Rādhārāṇī in order to be recognized as loving servitors of Śrī Kṛṣṇa.” (CC Adi 4.56 Purport)
“Lord Caitanya Mahāprabhu personally approaches the fallen conditioned souls of the iron age to deliver the highest principle of transcendental relationships with the Lord. The activities of Lord Caitanya are primarily in the role of the pleasure-giving portion of His internal potency.” (CC Adi 4.56 Purport)
Thus, we understand that the purpose of Śrī Caitanya Mahāprabhu’s appearance in Kaliyuga is twofold—external and internal. The external purpose is to propagate the yuga-dharma in the form of nāma-saṅkīrtana for the deliverance of people. The internal cause is to taste the intimate sweetness of prema-rasa, specifically of Rādhā’s bhāva, and in doing so, to propagate a new way of devotion called rāga-mārga.
The primary reason, the internal reason, is far more significant, because it is motivated from within Godhead. The external cause is dependent on the outside circumstance, i.e., an imbalance in dharma caused by unrighteous people. Kṛṣṇa chose a time to descend in order to taste the love experienced by Rādhā that coincided with the external reason.
All glories to Sri Caitanya Mahaprabhu!
All glories to Srila Prabhupada!