I see you, you see me. I touch you, you touch me. I taste something. This is gross. Above this gross there is mental platform. So mantra is also on the mental, which is little above intelligence and above that there is spiritual platform. So if on the mental platform, the mantra can act so wonderfully, how much spiritually the mantra can benefit you. You have to simply imagine. So this Hare Krishna mantra is completely spiritual. If you chant it, spiritually enlightened, then surely it will act.
Lecture on Srimad-Bhagavatam 1.7.19 — Vrndavana, September 16, 1976
A devotee is not afraid of going to hell if he has the opportunity to hear the glories of the Lord constantly. This is the advantage of chanting Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare. One may be put in any condition, but God gives him the prerogative to chant Hare Krishna. In any condition of life, if one goes on chanting he will never be unhappy.
Purport on Srimad Bhagavatam 3.15.49
The dog is also sleeping on the side of a street without any difficulty and the king is sleeping on the palace, very nice apartment. A Krishna conscious person, he’s also sleeping. But there are different grades. The Krishna conscious person while sleeping, is chanting Hare Krishna. This can be done. If you practice this Hare Krishna, even in sleeping you’ll chant Hare Krishna. Everything depends on practice.
Lecture on Srimad-Bhagavatam 5.5.2 — Boston, April 28, 1969
So in this Kali-yuga, if you simply chant or even if you cannot chant – because that requires little fortune — if we simply hear, that will also help us. So these centers are meant for chanting and hearing about Krishna. Simply this process, chanting and hearing, will purify our existence.
Lecture on Srimad-Bhagavatam 3.26.16 — Bombay, December 25, 1974
The Krishna consciousness movement is chiefly engaged in chanting the maha-mantra all over the world. Sri Caitanya Mahaprabhu introduced the congregational chanting of the Hare Krishna mantra to give everyone a chance to hear Krishna’s holy name, for simply by hearing Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare/ Hare Rama, Hare Rama, Rama Rama, Hare Hare, one becomes purified (ceto-darpana-marjanam).
Chaitanya Caritamrta Antya Lila 20.12 – Purport
One must read Srimad Bhagavatam regularly and with scrutiny to gradually become attached to the chanting of the Hare Krishna maha mantra.
Purport on Chaitanya Caritamrta Adi Lila 7.73