In the Padma Purana it is said, "The Lord may offer liberation or material happiness to a devotee, but after some devotional service has been executed, particularly in Mathura during the month of Karttika, the devotees want only to attain pure devotional service unto the Lord." The purport is that the Lord does not award devotional service to ordinary persons who are not serious about it. But even such unserious persons who execute devotional service according to the regulative principles during the month of Karttika, and within the jurisdiction of Mathura in India, are very easily awarded the Lord's personal service.
From NoD ch. 12