For an ordinary man, worship of Śrī Caitanya and Nityānanda Prabhu or the Pañca-tattva is easier than the worship of Rādhā and Kṛṣṇa. Unless one is very fortunate, he should not be induced to worship Rādhā-Kṛṣṇa directly. A neophyte student who is not sufficiently educated or enlightened should not indulge in the worship of Śrī Rādhā and Kṛṣṇa or the chanting of the Hare Kṛṣṇa mantra. Even if he does so, he cannot get the desired result. One should, therefore, chant the names of Nitāi-Gaura and worship Them without false prestige. Since everyone within this material world is more or less influenced by sinful activities, in the beginning, it is essential that one take to the worship of Guru-Gaurāṅga and ask their favor, for thus despite all his disqualifications one will very soon become qualified to worship the Rādhā-Kṛṣṇa vigraha.
It should be noted in this connection that the holy names of Lord Kṛṣṇa and Gaurasundara are both identical with the Supreme Personality of Godhead. Therefore one should not consider one name to be more potent than the other. Considering the position of the people of this age, however, the chanting of Śrī Caitanya Mahāprabhu’s name is more essential than the chanting of the Hare Kṛṣṇa mahā-mantra because Śrī Caitanya Mahāprabhu is the most magnanimous incarnation and His mercy is very easily achieved. Therefore one must first take shelter of Śrī Caitanya Mahāprabhu by chanting śrī-kṛṣṇa-caitanya prabhu-nityānanda śrī-advaita gadādhara śrīvāsādi-gaura-bhakta-vṛnda. By serving Gaura-Nityānanda one is freed from the entanglements of material existence and thus becomes qualified to worship the Rādhā-Kṛṣṇa Deity.
Ref >> Srila Prabhupada Vani.