It is confirmed in the Srimad-Bhagavatam, as you might have seen it, that one who hears about Krishna, for him, Krishna helps in various ways and the first thing is that He cleanses the mind of all dusty matter and by continuing such chanting and by reading regularly Srimad-Bhagavatam, one becomes gradually freed from the influence of passion and ignorance, and thus becomes situated in goodness. In such platform one can engage oneself in serious devotional service, and thus one becomes illuminated with the transcendental knowledge of Krishna. This stage is called liberated stage, and at this time one becomes freed from all doubts and material bondage, and thus his life becomes successful.
Letter to Harivilasa, 10 June, 1968