The more we are happy in Krishna Consciousness the more we become purified.
Just meditating on Gaura lila in the mind will purify us so much, because there is no question of committing offences.
The Sankirtana movement we have started offers the best process for becoming purified of all sinful reactions and coming immediately to the platform of spiritual life.
Srimad Bhagavatam 6.2.11
By performing congregational chanting of the Hare Krishna mantra, one can destroy the sinful condition of material existence, purify the unclean heart and awaken all varieties of devotional service.
Chaitanya Caritamrta on Antya Lila 20.13
We get purified when we take anxiety for Krishna.
So in this Kali-yuga, if you simply chant or even if you cannot chant – because that requires little fortune — if we simply hear, that will also help us. So these centers are meant for chanting and hearing about Krishna. Simply this process, chanting and hearing, will purify our existence.
Lecture onSrimad-Bhagavatam 3.26.16 — Bombay, December 25, 1974