Understanding God requires devotion, not speculation; He is simultaneously greatest and smallest.Listen — Srila Prabhupada Uvaca
Bhagavad-gītā 4.1 — November 10, 1971, Delhi 711110BG-DELHI [62:45 Minutes] Bg-04.01_711110BG-DELHI Prabhupāda: ...by Lord Kṛṣṇa, the Supreme Personality of Godhead, five thousand years ago... Not five thousand years ago. It is stated in the Bhagavad-gītā that before it was explained to Arjuna, it was formerly explained to the sun-god. imaṁ vivasvate yogaṁ proktavān aham avyayam vivasvān manave prāha manur ikṣvākave 'bravīt [Bg. 4.1] 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. Aṇḍāntara-stha-paramāṇu-cayāntara-stham [Bs. 5.35]. Aṇḍa, aṇḍa means this universe. God is within this universe. Just like in your body, you are present, as I was going to explain, dehino 'smin yathā dehe [Bg. 2.13].
Asmin dehe, within this body, there is the proprietor of the body, the soul. Similarly, this gigantic body of universe, cosmic manifestation, there is the Supersoul, therefore it is working. Just like in your body or in my body, because the soul is there, therefore it is active, it is moving. Similarly, this gigantic universal body there is God, Supersoul.
Two kinds of soul: one Supersoul and one individual soul. We are living entities, we are individuals, and God is Supersoul. What is the difference between Supersoul and individual soul? One is very small, minute, and the other is very big. God is great.
Aṇor aṇīyān mahato mahīyān [Kaṭha Upaniṣad 1.2.20]: God is greater than the greatest. You can conceive, in your idea, the greatness of something, but God is still greater. And you can conceive the smallest—just like the atom—yet God is smaller than the atom. That is God. Not that He's only the great, but He is the smallest also.