With our lips we should be chanting with our ears we should be hearing and with our heart we should be crying out for the Lord like a baby does for its mother.
Chaitanya Mahaprabhu has recommended that everyone should chant the Hare Krishna mantra just to cleanse the dust from the heart. If the dust of the heart is cleansed away, then one can actually understand the importance of the holy name.
Let people chant the Hare Krsna mantra constantly. Then their demoniac tendencies will be killed, and they will become first-class devotees, happy in this life and in the next.
Srimad Bhagavatam 6.2.14,
Chanting is the waxing moon that spreads the white lotus of good fortune for all living entities.
Sri Chaitanya Caritamrta, Antya 20.12,
Just by chanting the holy names of Lord Krishna, all inauspiciousness disappears.
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,