if we follow Krsna, not only we are chanting
Hare Krsna Hare Krsna Krsna Krsna Hare Hare
Hare Rama Hare Rama Rama Rama Hare Hare
but we have to follow the principles laid down in the Bhagavad-gita. That will make our life successful. Practically we have to apply this, have to apply the principle. Otherwise the whole attempt will be failure.
From Srila Prabhupada's lecture on Bhagavad-gita 3.21-25 — New York, May 30, 1966