Krsna is God. We are His servants. When we want to become God, we are put into the material world where we can have an illusion of being Krsna, or being the Supreme purusa -enjoyer. God however cannot become God. Krsna is God eternally. As soon as God becomes subjected to change, he cannot be considered the Supreme.
Sri Caitanya Mahaprabhu says that the actual position of the living entity is that of eternal servant of the Supreme Lord. Forgetting this principle, the living entity becomes conditioned by material nature, but in serving the Supreme Lord, he becomes the liberated servant of God. The living entity’s constitutional position is to be servitor; he either has to serve the illusory māyā or the Supreme Lord. If he serves the Supreme Lord, he is in his normal condition, but if he prefers to serve the illusory external energy, then certainly he will be in bondage. In illusion the living entity is serving in this material world. He is bound by his lust and desires, yet he thinks of himself as the master of the world. This is called illusion. When a person is liberated, his illusion is over, and he voluntarily surrenders unto the Supreme to act according to His desires. The last illusion, the last snare of māyā to trap the living entity, is the proposition that he is God. The living entity thinks that he is no longer a conditioned soul, but God. He is so unintelligent that he does not think that if he were God, then how could he be in doubt? That he does not consider. For God, or the Supreme Personality of Godhead Krsna is Absolute. Krsna contains everything what is within our exprience and everything what is beyond our experience. This involves His all-cognizant feature. In other words, Krsna is supremely conscious. We might be conscious of pains and pleasures of our body, but we are never conscious of pains and pleasures of other's bodies. But Krsna, being all-cognizant, is aware of all the psychological movements of everything conscious in all the universes of His creation and His spiritual abode. Therefore He knows everything. Not just that. Because Krsna is not subjected to material energy and therefore not subjected to material time, which divides eternal time into past, present and future, He also knows what is going to happen in the future and knows everything what has happened in the past. Doubt means ignorance and although Krsna also allows Himself to be illusioned or subjected to transcendental ignorance by His yoga maya potency, He never looses His all-cognizant nature. In other words, He's simultaneously ignorant and all-cognizant if He wishes to. Who is that rascal who can still think after considering all these different points that He has become God?
