We are chanting Hare Krsna maha-mantra, but if we become at least once in life in ecstasy in chanting Hare Krsna, then all our sinful reaction of life is finished. Unfortunately, we again commit sinful life. Otherwise, by chanting once Hare Krsna mantra, one becomes immediately free from the reaction.
But maya is so powerful that it induces again to commit sinful life.
From Srila Prabhupada's lecture on Srimad-Bhagavatam 6.1.19 — May 19, 1976, Honolulu