A sincere student aurally receives the holy name from the spiritual master, and after being initiated he follows the regulative principles given by the spiritual master. When the holy name is properly served in this way, automatically the spiritual nature of the holy name spreads; in other words, the devotee becomes qualified in offenselessly chanting the holy name. When one is completely fit to chant the holy name in this way, he is eligible to make disciples all over the world, and he actually becomes jagad-guru. Then the entire world, under his influence, begins to chant the holy names of the Hare Krsna maha-mantra. Thus all the disciples of such a spiritual master increase in attachment for Krsna, and therefore he sometimes cries, sometimes laughs, sometimes dances and sometimes chants. These symptoms are very prominently manifest in the body of a pure devotee.

From Srila Prabhupada's purport to Cc Adi 7.83