Following The Footprints Of Lord Chaitanya - Prabhupada 1042
Just like in the material world, in the world of duality there is difference between the name "water" and the substance water. The name water is different from the substance water. If you are thirsty, if you simply chant "water, water, water, water," your thirstiness will not be quenched. You require the substance water. That is material. But spiritually, the name Kṛṣṇa or the name Allah or the name Jehovah is as good as the Supreme Personality of Godhead.
Therefore if you chant Hare Kṛṣṇa . . . you may inquire why we are chanting Hare Kṛṣṇa. Hare Kṛṣṇa, this name, was chanted by Lord Caitanya, who introduced this movement five hundred years ago in India. We are following the footprints of Lord Caitanya.