One’s memory of Krishna is revived by chanting the maha-mantra, Hare Krishna. By this practice of chanting and hearing the sound vibration of the Supreme Lord, one’s ear, tongue and mind are engaged.
Bhagavad-Gita 8.8,
Srila Prabhupada
Simply by chanting the holy name of Krishna – Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare – a devotee of the Lord can approach the supreme destination easily and happily, but this destination cannot be approached by any other process of religion.
Bhagavad-Gita 12.6-7,
Srila Prabhupada
The impersonal sound of Krsna is OM,but the sound Hare Krsna contains OM.
Bhagavad-Gita 8.13,
Srila Prabhupada
This temporary life is full of miseries. Take shelter of the holy name as your only business.