The first condition is that worldly desires should not be there—this is the first condition. Secondly, a relationship with Kṛṣṇa should be there. No offenses should exist. Any kind of offenses—or anarthas —should not be there. Most importantly, there should be a relation with Kṛṣṇa. Then, when we chant, ceto darpaṇa mārjanam will take place, otherwise not. The heart will not be vast to accommodate loving sentiments for Śrī Rādhā Kṛṣṇa. But (1) if the practitioner has been initiated by any bona fide guru and (2) the guru has really accepted the disciple and (3) given a relation between the jīva and Kṛṣṇa, and (4) he is somewhat realizing his relationship with Kṛṣṇa, (5) chanting without any offenses, (6) no anarthas and worldly requirements are there, then (7) ceto-darpaṇa-mārjanam will manifest.
ānandāmbudhi-vardhanaṁ prati-padaṁ pūrṇāmṛtāsvādanaṁ
sarvātma-snapanaṁ paraṁ vijayate Śrī-Kṛṣṇa-saṅkīrtanam
July 21, 1996 Boven-Leeuwen, Netherlands