Basic Principle of Spiritual Advancement
Lord Chaitanya has given special stress to chanting of these holy names of the Lord as the basic principle of spiritual advancement.
Purport on Srimad Bhagavatam 3.29.18
Anything & Everything
Holy name can give you anything and everything.
Seeing The Supreme Lord Directly
Performing kirtana and hearing the vibration of the sound Hare Krishna is actually seeing the Supreme Personality of Godhead directly.
Purport on Srimad Bhagavatam 7.4.25-26
Deriving The Actual Benefit From This Human Form
If one wants to derive the actual benefit from this human form, he must take to the chanting of the holy name of the Lord.
Purport on Srimad Bhagavatam 7.6.19
Chanting
If one chants the holy name of the Lord just to make a show, not knowing the secret of success, he may increase his bile secretion, but he will never attain perfection in chanting the holy name.
Purport on Chaitanya Caritamrta Adi Lila 7.95-96
Progressing in Spiritual Life in Different Yugas
Caitanya Caritamrta on Progressing in Spiritual Life in Different Yugas: For progress in spiritual life, the sastras recommend meditation in Satya-yuga, sacrifice for the satisfaction of Lord Visnu in Treta-yuga and gorgeous worship of the Lord in the temple in Dvapara-yuga, but in the Age of Kali one can achieve spiritual progress only by chanting the holy name of the Lord.
Purport on Caitanya Caritamrta Adi Lila 7.76