Since All The Powers Are There in Krishna’s Name, Why Just One Round is Not Sufficient?
Actually, why would one even have to chant one round? One pure utterance of the two syllables "Krish-na" is sufficient to deliver the sincere chanter from millions and billions of lifetimes of sinful activities and transport him back to the spiritual sky for reviving his original loving relationship with the Supreme Personality of Godhead, the source of all existence. But the difficulty is that our chanting is not of a very pure quality. It is because of our impurities that we require to utter Lord's holy names constantly. That is Krishna's instructions. Because we are not able to do this the spiritual master mercifully gives us the concession that we can become fully Krishna conscious by chanting at least 16 rounds daily of the Hare Krishna mantra on japa mala beads along with the strict avoidance of illicit sex, meat eating, intoxication, and gambling. In short, when you have got a lot a dirt, a lot of cleaning is require.
