A.C. Bhaktivedanta Swami Prabhupada
Yoga means to connect ourself again with God, or Krishna. This practice of yoga, always thinking of Krishna, is very easily accomplished by chanting Hare Krishna maha-mantra, if you chant Hare Krishna, Hare Krishna, Krishna Krishna, Hare Hare, Hare Rama, Hare Rama, Rama Rama, Hare Hare. Twenty-four hours it can be practiced. There is no expenditure, there is no loss, but the gain is very great.
From a lecture by Srila Prabhupada, Bhagavad-gita 7.1 — Durban, October 9, 1975
A.C. Bhaktivedanta Swami Prabhupada
If one wants to achieve success at the end of his life, the process of remembering Krishna is essential. Therefore one should constantly/incessantly chant the Maha Mantra.
Mahanidhi Swami
Practical action is the best way to show our determination. So while chanting, we should show our determination to be attentive. This attracts Krishna's attention.
Lokanath Swami
By chanting of Hare Krishna, you have the Lord with you and He satisfies you. He pleases you. You are pleased with your Lord. He is also the Lord of your heart.
Srimad Bhagavatam
The chanting of the Hare Krishna mantra is recommended even for persons who commit offenses, because if they continue chanting they will gradually chant offenselessly.
Purport on Srimad Bhagavatam 6.3.24
Srimad Bhagavatam
One has to continue chanting the Hare Krishna mantra and preaching the chanting of this mantra because such preaching and chanting constitute the perfection of life.
Purport on Srimad Bhagavatam 4.24.67