"When one seriously engages in the devotional service of the Personality of Godhead, fixing the Lord's lotus feet within one's heart as the only goal of life, one can destroy the innumerable impure desires lodged within the heart as a result of one's previous fruitive work within the three modes of material nature. When the heart is thus purified one can directly perceive both the Supreme Lord and one's self as transcendental entities. Thus one becomes perfect in spiritual understanding through direct experience, just as one can directly experience the sunshine through normal, healthy vision."
[ SB. 11.3.40 purport ]