I request you to continue following all of the regulative principles staunchly and encourage all other of my disciples in your preaching area to do the same. This is the most important thing. As soon as one discontinues his staunch following of the regulative principles such as no meat eating, no illicit sex, no intoxication, no gambling, rising early before 4:00, coming to mangala arati, chanting at least 16 rounds, etc., then his spiritual life is hampered and there is a chance that at any time he may become a victim of maya.

(From Srila Prabhupada's letter to Revatinandana – Bombay 15 December 1974)