The basic principle is love. So similarly, our full surrender, full Krsna consciousness, can be achieved when we develop our love for Krsna little by little, little by little, and then come to the perfection. When we come to the perfection, then we cannot live without Krsna. Just like Caitanya Mahaprabhu taught us. In the last stage of His life He exhibited such manifestation of love that He was dying without Krsna. Sunyayitam jagat sarvam govinda-virahena me [Siksastaka 7]. Sunyayitam. Sunyayitam, "everything is vacant." Sunyayitam jagat sarvam govinda-virahena me. "Without Govinda, I see everything vacant." Sometimes we have got experience. If we lose a friend, a son, at that time everything becomes vacant without my son, without my lover. That is practical. So Sri Caitanya Mahaprabhu was exhibiting that type of love for Krsna, that He was feeling that "Without Krsna, everything is void." Sunyayitam jagat sarvam govinda-virahena me. This He taught personally, how to raise oneself to the topmost stage of love for Krsna. That is the ultimate aim and object of life.

From Srila Prabhupada's lecture on Srimad-Bhagavatam 3.26.40 — January 15, 1975, Bombay