by Subhag Swami

Prabhupada is writting in his book - "I am writing this narration of pastimes and attributes of Lord Chaitanya by the mercy of Chaitanya Mahaprabhu and his associates. I don't know how to write properly. But I am purifying myself by writing this description." This is a way of teaching us. I shouldn't be proud of thinking  that I am writing, instead we should think that God has given me this opportunity to serve by writing to purify myself. So I am getting purified by doing this service. One who is saying, "I have done this, and I have achieved this", is simply doing "karma-kanda". 
Srila Bhakti Siddhanta Thakur says that one who thinks, "I have done this, I have done that, What have you done? He is doing "Karma-kanda" (fruitive activities). 
One who really does (devotional service) is very humble. He gives all the credit to God. He thinks that I am not doing anything. God is making me an instrument to do this service, thereby I am getting purified. This is the attitude (of a humble devotee). Otherwise one is doing 'Karma-kanda' (fruitive activities). Is that clear? so one should never take the credit saying that I have done this, I have done that. You are in a mode, and accordingly you are acting. You simply have to carry out the order of higher authority, and thereby you become purified. You will become humble. Unless you become purified, lord won't take your service. Lord is Supremly pure as stated in Bhagavad Gita :-
arjuna uvaca
param brahma param dhama
pavitram paramam bhavan
Arjuna said, "You are the Supreme Personality of Godhead, the ultimate abode, the purest, the Absolute Truth."
 So this is not  just a book word and academic knowledge. We have to have change of consciousness and change of heart. Is your heart changed? This is not so easy. That's why Chaitanya Mahaprabhu says, "Clean your heart".

cheto-darpana-marjanam bhava-maha--davagni-nirvapanam
shreyah-kairava-chandrika-vitaranam vidya-vadhu-jivanam
anandambudhi-vardhanam prati-padam purnamritaswadanam
sarvatma-snapanam param vijayate sri-krishna-sankirtanam

'Let there be all victory for the chanting of the holy name of Lord Krsna, which can cleanse the mirror of the heart and stop the miseries of the blazing fire of material existence. That chanting is the waxing moon that spreads the white lotus of good fortune for all living entities. It is the life and soul of all education. The chanting of the holy name of Krsna expands the blissful ocean of transcendental life. It gives a cooling effect to everyone and enables one to taste full nectar at every step.

Translation: Bhakta Anirban

Editing: Ramanand das