The Supreme Lord said: My dear Cousin Arjuna, because you are never envious of Me, I shall impart to you this most secret wisdom, knowing which you shall be relieved of the miseries of material existence. In the Bhagavata-purana it is said that religious people generally do not know that the highest perfection of religion is the attainment of the stage of devotional service. Generally spiritually transcendent knowledge is required for the understanding of the path of self-realization. It is said here that this devotional service is eternally existing. It is not as the Maya-vadi [aka atheist mystics] philosophers claim. They sometimes take to so-called devotional service, and as long as they are not liberated they continue their devotional service, but at the end, when they become liberated, they "become one with God." Such temporary time-serving devotional service is not accepted as pure devotional service. Actual devotional service continues even after liberation. When the devotee goes to the spiritual planet in the kingdom of God, he is also engaged there in serving the Supreme Lord. He does not try to become one with the Supreme Lord. As it will be seen, actual devotional service begins after liberation.After being liberated, or being situated in the Brahman position, one's devotional service begins. By executing devotional service, one can understand the Supreme Lord. No one can understand the Supreme Personality of Godhead by executing works, acquiring esoteric knowledge, or ascetic austeritiesor any other yoga path independantly. Without coming to the stage of devotional service, one cannot understand what is the Personality of Godhead. In the Bhagavata-purana it is also confirmed that when one becomes purified by executing the process of devotional service, especially by hearing from realized souls, then he can understand the science of God. When one's heart is cleared of all nonsense, then one can understand what God is. Thus the process of devotional service is the king of all education and the king of all confidential knowledge. It is the purest form of religion, and it can be executed joyfully without difficulty. Therefore one should adopt it.