At the present moment people are denying the existence of God, or they are thinking that God is dead. That means imperfection of knowledge. They have to still make progress to the perfectional point. And that test is to understand, "Here is God, and He is the fountainhead of everything." That perfection of knowledge you will have simply by reading... Any scripture you can read. The same conception is there. But in the Bhagavad-gītā it is more clearly explained so that you can understand with all reason, arguments, and scrutiny too. It is not dogmatic. That is the beauty of Bhagavad-gītā.
Just like in some dictionary the word is explained in one word. In some dictionary it is explained that "The history of this world is like this. This word can be explained like this, like that, like that," some pages like that. Similarly, so far dictionary, the small pocket dictionary is also dictionary, and that Webster's International big dictionary, that is also dictionary. The difference is that international dictionary, you get details of one word. Similarly, any scripture is perfectly giving direction towards understanding what is God. But actually how God is great, how He is working, how His laws are working, all these things you can find in the Bhagavad-gītā and Śrīmad-Bhāgavatam.
(Lecture on Bhagavad-Gita-4:8--Montreal, 14th. june, 1968).

Although illusory energy is also part and parcel of the Supreme Lord, illusory energy is differentiated from the Lord. The illusory energy is not, however, false, as claimed by the monist philosophers. The rope accepted as a snake may be an illusion to a particular person, but the rope is a fact, and the snake is also a fact. The illusion of water on the hot desert may be illusion for the ignorant animal searching for water in the desert, but the desert and water are actual facts. Therefore the material creation of the Lord may be an illusion to the nondevotee, but to a devotee even the material creation of the Lord is a fact, as the manifestation of His external energy. But this energy of the Lord is not all. The Lord has His internal energy also, which has another creation known to be the Vaikuṇṭhalokas, where there is no ignorance, no passion, no illusion and no past and present. With a poor fund of knowledge one may be unable to understand the existence of such things as the Vaikuṇṭha atmosphere, but that does not nullify its existence.
(Srimad Bhagavatam--2:9:10--purport).

The Lord, as Supersoul, pervades all things, just as fire permeates wood, and so He appears to be of many varieties, though He is the absolute one without a second.
Lord Vāsudeva, the Supreme Personality of Godhead, by one of His plenary parts expands Himself all over the material world, and His existence can be perceived even within the atomic energy. Matter, antimatter, proton, neutron, etc., are all different effects of the Paramātmā feature of the Lord. As from wood, fire can be manifested, or as butter can be churned out of milk, so also the presence of the Lord as Paramātmā can be felt by the process of legitimate hearing and chanting of the transcendental subjects which are especially treated in the Vedic literatures like the Upaniṣads and Vedānta. Śrīmad-Bhāgavatam is the bona fide explanation of these Vedic literatures. The Lord can be realized through the aural reception of the transcendental message, and that is the only way to experience the transcendental subject. As fire is kindled from wood by another fire, the divine consciousness of man can similarly be kindled by another divine grace. His Divine Grace the spiritual master can kindle the spiritual fire from the woodlike living entity by imparting proper spiritual messages injected through the receptive ear. Therefore one is required to approach the proper spiritual master with receptive ears only, and thus divine existence is gradually realized. The difference between animality and humanity lies in this process only. A human being can hear properly, whereas an animal cannot.
(Srimad Bhagavatam-1:2:32--translation and purport).