Simply by chanting the holy name of Lord Krishna, one can be freed from all undesirable habits. This is the means of awakening all good fortune and initiating the flow of waves of love for Krishna.
Chaitanya caritamrita Antya Lila 20.11
In this age, chanting of Hare Krishna Mantra is the prime business of the devotee, and preaching of this Hare Krishna Mantra by outdoor Sankirtana and propagation of literature is our more important business. Side by side, Deity worship is recommended, but when there is a question of accepting one of them, we shall prefer to accept chanting of Hare Krishna Mantra first.
Letter to Hamsaduta – Hamburg 5 September, 1969.
Sukadeva Goswami says, this age is an ocean of faults, but there is one boon, in this age one gets the same result as was achieved in former ages through elaborate temple worship, costly sacrifices, or introspective meditation, simply by chanting the Holy Name of The Lord.
Letter to Achyutananda, 1975.
Everyone should be given a chance to take prasada and thus be induced to chant the holy names of Hare Krishna and also dance in ecstasy. By these three processes, although performed without knowledge or education, even even a dog went back to Godhead.
Chaitanya Caritamrta Antya Lila 1.32
Sankirtana means chanting of the holy name of the Lord.
Purport on Srimad Bhagavatam 7.15.7
As our heart is always silently beating and connecting us with the life in the material body, we should always be connected with Krsna's name and have life in our spiritual body. The holy name is the heart beat of the spiritual body, the soul beat.