By His practical activity, Sri Caitanya Mahaprabhu informed us how to cleanse our hearts. Once the heart is cleansed, we should invite Lord Sri Krsna to sit down, and we should observe the festival by distributing prasadam and chanting the Hare Krsna maha-mantra. Sri Caitanya Mahaprabhu used to teach every devotee by His personal behavior. Everyone who spreads the cult of Sri Caitanya Mahaprabhu accepts a similar responsibility. The Lord was personally chastising and praising individuals in the course of the cleaning, and those who are engaged as acaryas must learn from Sri Caitanya Mahaprabhu how to train devotees by personal example. The Lord was very pleased with those who could cleanse the temple by taking out undesirable things accumulated within. This is called anartha-nivrtti, cleansing the heart of all unwanted things. Thus the cleansing of the Gundica-mandira was conducted by Sri Caitanya Mahaprabhu to let us know how the heart should be cleansed and soothed to receive Lord Sri Krsna and enable Him to sit within the heart without disturbance.

Srila Prabhupada, CC Madhya 12.135, ppt.