It is essential for persons who are actually liberated to hear about the pastimes of Krsna. That is the supreme relishable subject matter for one in the liberated state. Also, if persons who are trying to be liberated hear such narrations as the Bhagavad-gita and Srimad-Bhagavatam, then their path of liberation becomes very clear. The Bhagavad-gita is the preliminary study of Srimad-Bhagavatam. By studying the Gita, one becomes fully conscious of the position of Lord Krsna; and when he is situated at the lotus feet of Krsna, he understands the narrations of Krsna as described in Srimad-Bhagavatam. Lord Caitanya has therefore advised His followers that their business is to propagate krsna-katha.

Krsna-katha means narrations about Lord Krsna. There are two krsna-kathas: narrations spoken by Krsna and narrations spoken about Krsna. The Bhagavad-gita is the narration or the philosophy on the science of God, spoken by Krsna Himself. Srimad-Bhagavatam is the narration about the activities and transcendental pastimes of Krsna. Both are krsna-katha. It is the order of Lord Caitanya that krsna-katha should be spread all over the world, because if the conditioned souls, suffering under the pangs of material existence, take to krsna-katha, then their path of liberation will be open and clear. The purpose of presenting this book is primarily to induce people to understand Krsna or krsna-katha, because thereby they can become freed from material bondage.

Srila Prabhupada; Krsna Book, Introduction