If after accepting the spiritual master and being initiated one does not follow the rules and regulations of devotional service, then he is again fallen.
A bona fide spiritual master, under the guidance of authorities, can turn anyone to the Vaisnava cult so that naturally he may come to the topmost position of a brahmana.
One must execute devotional service under the guidance of a devotee or directly under the guidance of the Supreme Personality of Godhead. It is not possible, however, to train oneself without guidance from the spiritual master.
In spiritual life, one must conduct one's whole life under the guidance of the guru. Only one who executes his spiritual life under the direction of the spiritual master can achieve the mercy of Krishna.