“Vaishnava” means servant of the Vaishnava. A Vaishnava always meditates on serving guru. Everything a Vaishnava does is intended as an act of service, and because a Vaishnava is always serving the guru’s mood, preaching becomes successful. When this dynamic is intact, the Lord agrees to come. Srila Prabhupada was such a glorious Vaishnava that he fulfilled this criterion and worked tirelessly in his Guru Maharaja’s service, always meditating on his guru’s order.