Sometimes river flows very strong, sometimes it flows very small, but it makes no difference to the ocean because it is satisfied in itself with its own quantity of water. Similarly, when our heart is cleansed with spirituality, we find pleasure and ecstasy with our own selves that is so sweet, so wonderful and so satisfying, that the so-called pleasures of this world no longer have any values, no appeal at all.
The ultimate goal of Bhakti is to get Krishna and we get it by taking shelter of the holy name.
The holy name of Krishna has extraordinary spiritual potency because the name of God is nondifferent from God Himself.
Sri Namamrita – The Nectar of the Holy Name,
The highest summit of spiritual perfection is knowledge of the Supreme Personality of Godhead.
Bhagavad Gita 10.7,
This chanting of the Hare Krishna mantra is enacted from the spiritual platform and thus this sound vibration surpasses all lower strata of consciouness – namely sensual, mental and intellectual.
Krishna Consciousness The Topmost Yoga System,
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