Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. In Kali-yuga, if this Vedic maha-mantra is chanted regularly and heard regularly by the devotional process of shravanam kirtanam, it will purify all societies, and thus humanity will be happy both materially and spiritually.
Srimad Bhagavatam 4.18.14,
When we hear about the Lord, we should hear with a spirit to serve the Lord. When we chant his names, we should chant so that He is pleased to hear us chanting. That is the beauty of life, the real art of living.
In this material world there are only two representatives of the Supreme Personality of Godhead; the transcendental sound vibration of the Holy Name and his eternally transcendental deity incarnation.
The best means of spiritual realization is chanting the holy name of the Lord.
Bhagavad Gita 6.11-12,
A Vaishnava bestows the priceless gift of the mahamantra, Hare Krishna Hare Krishna Krishna Krishna Hare Hare/ Hare Rama Hare Rama Rama Rama Hare Hare. Simply by chainting this mantra one can remain in a liberated state.
The Matchless gift, Chapter-7,
Living beings who are entangled in the complicated meshes of birth and death can be freed immediately by even unconsciously chanting the holy name of Krishna, which is feared by fear personified. — Srimad Bhagavatam, 01.01.15.