Lord Caitanya is described as follows: He is the only shelter for the forlorn, the most fallen, and He is the only hope for those who are completely devoid of spiritual knowledge. Let us try to discuss His great contribution of devotional service.
The supremely powerful Lord Kṛṣṇa becomes manifest in five different features. Although He is one without a second, in order to serve five specific spiritual purposes, He becomes manifest in five ways. Such diversity is eternal and blissful, in contrast to the conception of monotonous oneness. From the Vedic literature we can understand that the Absolute Truth, the Supreme Personality of Godhead, eternally exists with His diverse energies. Lord Caitanya appeared with full diverse energies, and they are five in number; therefore Lord Caitanya is said to be Kṛṣṇa with diverse energies.
There is no difference between the energy and the energetic in regard to the Lord's appearance as Śrī Caitanya Mahāprabhu and His four associates Nityānanda Prabhu, Advaita Prabhu, Gadādhara Paṇḍita and Śrīvāsa Ṭhākura. Among these five diverse manifestations of the Supreme Lord (as the Lord Himself and His expansion, incarnation, devotional energy and devotee) there is no spiritual difference. They are five in one Absolute Truth. For the sake of relishing transcendental flavors in the Absolute Truth, there are five diverse manifestations. These are called the form of a devotee, the identity of a devotee, the incarnation of a devotee, the devotional energy and the pure devotee.
Out of the five diversities in the Absolute Truth, the form of Lord Caitanya is that of the original Personality of Godhead, Kṛṣṇa. Lord Nityānanda is the manifestation of the first expansion of the Supreme Lord. Similarly, Advaita Prabhu is an incarnation of the Supreme Lord. These three—Caitanya, Nityānanda and Advaita—belong to the category of viṣṇu-tattva, or the Supreme Absolute Truth. Śrīvāsa represents the pure devotee, and Gadādhara represents the internal energy of the Lord for the advancement of pure devotion. Therefore Gadādhara and Śrīvāsa, although on the Viṣṇu platform, are dependent, diverse energies of the Supreme Lord. In other words, they are not different from the energetic, but they are manifest diversely for the sake of relishing transcendental relationships. The whole process of devotional service involves a transcendental reciprocation of the flavors of relationship between the worshiper and the worshiped. Without such a diverse exchange of transcendental flavors, devotional service has no meaning.