CC Madhya 7.101
ei-mata ‘vaiṣṇava’ kaila saba nija-grāma
Such an empowered person would request everyone and anyone — whomever he saw — to chant the holy name of Kṛṣṇa. In this way all the villagers would also become devotees of the Supreme Personality of Godhead.
In order to become an empowered preacher, one must be favored by Lord Śrī Caitanya Mahāprabhu or His devotee, the spiritual master. One must also request everyone to chant the mahā-mantra. In this way, such a person can convert others to Vaiṣṇavism, showing them how to become pure devotees of the Supreme Personality of Godhead.