"If one chants the exalted holy name of the Lord again and again and yet his love for the Supreme Lord does not develop and tears do not appear in his eyes, it is evident that because of his offenses in chanting, the seed of the holy name of Krsna does not sprout.
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But if one only chants, with some slight faith, the holy names of Lord Caitanya and Nityananda, very quickly he is cleansed of all offenses. Then as soon as he chants the Hare Krsna maha-mantra, he feels the ecstacy of love for God."
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(Caitanya-caritamrta, Adi-lila 8.29-31)
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