Lord Kṛṣṇa said that before explaining the yoga system, bhakti-yoga system, to Arjuna, it was explained to the Sun-god Vivasvān, and Sun-god explained the same system to his son, Manu, and Manu explained the same system to his son, Ikṣvāku. Evaṁ paramparā-prāptam imaṁ rājarṣayo viduḥ (BG 4.2). Kṛṣṇa said that this system of knowledge is coming down by disciplic succession, sa kāleneha yogaḥ naṣṭaḥ parantapa. My dear Arjuna, although it was coming down by disciplic succession from spiritual master to the disciple, or from the father to the son, but in course of time, it is now lost. Therefore I am speaking the same yoga system to you, bhakto 'si priyo 'si me (BG 4.3), because you are my devotee. So, if we want to understand, if we want to know God, we have to become His devotee.
Devotee means servant—not paid servant—but servant by affection. Just like, these boys, European boys, American boys, and some of the Philippines boys, they are trying to serve me, but they are not paid servant. They are servant by affection. Just like father and mother becomes the servant of the sons. The son, the small child, passing stool, and the mother cleansing. That does not mean the mother has become sweeper. The mother is mother, but out of affection she is giving service. Similarly, when we give service to the Lord in affection, in love, then God reveals, ataḥ śrī-kṛṣṇa-nāmādi na bhaved grāhyam indriyaiḥ (CC Madhya 17.136). God's name, God's form, God's quality, God's pastimes, activities, are not understandable by our, these blunt material senses. We cannot see God with these eyes. God is present everywhere. God is present within your heart, God is present within this universe, God is present within the atom.