The Supreme Personality of Godhead is endowed with all six opulences in full, and moreover He is extremely kind to His devotee. Although He is full in Himself, He nonetheless wants all the living entities to surrender unto Him so that they may engage in His service. Thus He becomes satisfied. Although He is full in Himself, He nonetheless becomes pleased when His devotee offers Him patram puspam phalam toyam–a leaf, flower, fruit or water–in devotion. Sometimes the Lord, as the child of mother Yasoda, requests His devotee for some food, as if He were very hungry. Sometimes He tells His devotee in a dream that His temple and His garden are now very old and that He cannot enjoy them very nicely. Thus He requests the devotee to repair them. Sometimes He is buried in the earth, and as if unable to come out Himself, He requests His devotee to rescue Him. Sometimes He requests His devotee to preach His glories all over the world, although He alone is quite competent to perform this task. Even though the Supreme Personality of Godhead is endowed with all possessions and is self-sufficient, He depends on His devotees. Therefore the relationship of the Lord with His devotees is extremely confidential. Only the devotee can perceive how the Lord, although full in Himself, depends on His devotee for some particular work. This is explained in Bhagavad-gita (11.33), where the Lord tells Arjuna, nimitta-matram bhava savyasacin: “O Arjuna, merely be an instrument in the fight.” Lord Krishna had the competence to win the Battle of Kuruksetra, but nonetheless He induced His devotee Arjuna to fight and become the cause of victory. Sri Chaitanya Mahaprabhu was quite competent enough to spread His name and mission all over the world, but still He depended upon His devotee to do this work. Considering all these points, the most important aspect of the Supreme Lord’s self-sufficiency is that He depends on His devotees. This is called His causeless mercy. The devotee who has perceived this causeless mercy of the Supreme Personality of Godhead by realization can understand the master and the servant.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Sixth Canto, Chapter 19 – Text 05