When we think of superior person, we think he is superior because he knows something more than I, superiority means more knowledge. Krishna knows everything, and He claims that if anyone knows Him, then he also knows everything. So knowledge means to know only that Krishna is the Proprietor of everything that Krishna is the Friend of everyone, and that Krishna is the Enjoyer of everything. These three things: Proprietor, Friend, and Enjoyer. If somebody knows this, he is actually wise. Therefore because the devotee always knows this, he is more superior person because he has got all knowledge. But even more important than the knowledge of Krishna is the acting upon that knowledge, or devotional service. By the acting he realizes his knowledge and becomes complete.
Letter to Sri Govinda, 5 March, 1972