Whoever heard Lord Caitanya Mahaprabhu chant, “Hari, Hari,” also chanted the holy name of Lord Hari and Krsna. In this way, they all followed the Lord, very eager to see Him. After some time, the Lord would embrace these people and bid them to return home, after investing them with spiritual potency. Being thus empowered, they would return to their own villages, always chanting the holy name of Krsna and sometimes laughing, crying and dancing. These empowered people used to request everyone and anyone — whomever they saw — to chant the holy name of Krsna. In this way all the villagers would also become devotees of the Supreme Personality of Godhead.
PURPORT: In his Amrta-pravaha-bhasya, Srila Bhaktivinoda Thakura explains that this spiritual potency is the essence of the pleasure potency. By these two potencies, one is empowered with devotional service. Lord Krsna Himself, or His representative, the unalloyed devotee, can mercifully bestow these combined potencies upon any man. Being thus endowed with such potencies, one can become an unalloyed devotee of the Lord. Anyone favored by Lord Sri Caitanya Mahaprabhu was empowered with this bhakti-sakti. Thus the Lord’s followers were able to preach Krsna consciousness by divine grace…. In order to become an empowered preacher, one must be favored by Lord Sri Caitanya Mahaprabhu or His devotee, the spiritual master. One must also request everyone to chant the maha-mantra. In this way, such a person can convert others to Vaisnavism, showing them how to become pure devotees of the Supreme Personality of Godhead.
From translations & purports to Sri Caitanya-caritamrta Madhya-lila 7.98-101 by Srila Prabhupada