One should not confuse the three in their different capacities. One should not confuse the painter, the painting and the easel. This material world, which is the field of activities, is nature, and the enjoyer of nature is the living entity, and above them both is the supreme controller, the Personality of Godhead. It is stated in the Vedic language (in theŚvetāśvatara Upaniṣad 1.12), bhoktā bhogyaṁ preritāraṁ ca matvā/ sarvaṁ proktaṁ tri vidham-brahmam etat. There are three Brahman conceptions: prakṛti is Brahman as the field of activities, and the jīva (individual soul) is also Brahman and is trying to control material nature, and the controller of both of them is also Brahman, but He is the factual controller.
(Bhagavad-Gita-----13:3-----purport).

The Supreme Lord as the Supersoul is also stated in the Vedic literature (Śvetāśvatara Upaniṣad 6.16) to be pradhāna-kṣetrajña-patir guṇeśaḥ, the chief knower of the body and the master of the three modes of material nature. In the smṛti it is said, dāsa-bhūto harer eva nānyasyaiva kadācana. The living entities are eternally in the service of the Supreme Lord. This is also confirmed by Lord Caitanya in His teachings. Therefore the description of Brahman mentioned in this verse is in relation to the individual soul, and when the word Brahman is applied to the living entity, it is to be understood that he is vijñāna-brahma as opposed to ānanda-brahma. Ānanda-brahma is the Supreme Brahman Personality of Godhead.
(Bhagavad-Gita-----13:13-----purport).

The Supreme Lord, although the source of all the senses of the living entities, doesn't have material senses like they have. Actually, the individual souls have spiritual senses, but in conditioned life they are covered with the material elements, and therefore the sense activities are exhibited through matter. The Supreme Lord's senses are not so covered. His senses are transcendental and are therefore called nirguṇa. Guṇa means the material modes, but His senses are without material covering. It should be understood that His senses are not exactly like ours. Although He is the source of all our sensory activities, He has His transcendental senses, which are uncontaminated. This is very nicely explained in the Śvetāśvatara Upaniṣad (3.19) in the verse apāṇi-pādo javano grahītā.
(Bhagavad-Gita-----13:15-----purport).

It is clearly stated in the Vedic literature that because of His luminous effulgence, everything is illuminated. It is clear, therefore, that His situation is not in the material world. He is situated in the spiritual world, which is far, far away in the spiritual sky. That is also confirmed in the Vedic literature. Āditya—varṇaṁ tamasaḥ parastāt (Śvetāśvatara Upaniṣad 3.8). He is just like the sun, eternally luminous, but He is far, far beyond the darkness of this material world.
His knowledge is transcendental. The Vedic literature confirms that Brahman is concentrated transcendental knowledge. To one who is anxious to be transferred to that spiritual world, knowledge is given by the Supreme Lord, who is situated in everyone's heart. One Vedic mantra (Śvetāśvatara Upaniṣad 6.18) says, taṁ ha devam ātma-buddhi-prakāśaṁ mumukṣur vai śaraṇam ahaṁ prapadye. One must surrender unto the Supreme Personality of Godhead if he at all wants liberation. As far as the goal of ultimate knowledge is concerned, it is also confirmed in Vedic literature: tam eva viditvāti mṛtyum eti. "Only by knowing Him can one surpass the boundary of birth and death." (Śvetāśvatara Upaniṣad 3.8)
(Bhagavad-Gita-----13:18-----purport).

He is situated in everyone's heart as the supreme controller. The Supreme has legs and hands distributed everywhere, and this cannot be said of the individual soul. Therefore that there are two knowers of the field of activity—the individual soul and the Supersoul—must be admitted. One's hands and legs are distributed locally, but Kṛṣṇa's hands and legs are distributed everywhere. This is confirmed in the Śvetāśvatara Upaniṣad (3.17): sarvasya prabhum īśānaṁ sarvasya śaraṇaṁ bṛhat. That Supreme Personality of Godhead, Supersoul, is the prabhu, or master, of all living entities; therefore He is the ultimate shelter of all living entities. So there is no denying the fact that the Supreme Supersoul and the individual soul are always different.
(Bhagavad-Gita-----13:18-----purport).

The idea of this verse is very nicely expressed in the Kaṭha Upaniṣad (2.2.13) and Śvetāśvatara Upaniṣad (6.13). It is clearly stated there that above the innumerable living entities, some of whom are conditioned and some of whom are liberated, there is the Supreme Personality, who is Paramātmā. The Upaniṣadic verse runs as follows: nityo nityānāṁ cetanaś cetanānām. The purport is that amongst all the living entities, both conditioned and liberated, there is one supreme living personality, the Supreme Personality of Godhead, who maintains them and gives them all the facility of enjoyment according to different work. That Supreme Personality of Godhead is situated in everyone's heart as Paramātmā. A wise man who can understand Him is eligible to attain perfect peace, not others.
(Bhagavad-Gita-----15:17-----purport).

The Vaikuṇṭha planets and the Goloka Vṛndāvana planet are all self-illuminating, and the rays scattered by those sva-dhāma of the Lord constitute the existence of the brahma-jyotir. As further confirmed in the Vedas like the Muṇḍaka (2.2.10), Kaṭha (2.2.15) and Śvetāśvatara Upaniṣads (6.14):
na tatra sūryo bhāti na candra-tārakaṁ
nemā vidyuto bhānti kuto 'yam agniḥ
tam eva bhāntam anu bhāti sarvaṁ
tasya bhāsā sarvam idaṁ vibhāti
In the sva-dhāma of the Lord there is no need of sun, moon or stars for illumination. Nor is there need of electricity, so what to speak of ignited lamps? On the other hand, it is because those planets are self-illuminating that all effulgence has become possible, and whatever there is that is dazzling is due to the reflection of that sva-dhāma.
(Srimad Bhagavatam-----2:4:14-----purport).

Therefore the men of this insignificant planet should kindly accept the instruction of Brahmājī and would do well to surrender unto the lotus feet of the Lord rather than try to estimate the length and breadth of the Lord's potencies. His potencies are immeasurable, as confirmed in the Vedas. Parāsya śaktir vividhaiva śrūyate svābhāvikī jñāna-bala-kriyā ca (Śvetāśvatara Upaniṣad 6.8 (Cc. Madhya 13.65, purport)). He is the greatest of all, and all others, even the greatest of all living beings, namely Brahmājī, admits that the best thing for us is to surrender unto Him. Therefore only those persons with a very poor fund of knowledge claim that they themselves are lords of all that they survey.
(Srimad Bhagavatam-----2:6:36-----purport).

Arjuna was advised to receive transcendental knowledge from the realized person by surrender, questions and service. Receiving transcendental knowledge is not like exchanging dollars; such knowledge has to be received by service to the spiritual master. As Brahmājī received the knowledge directly from the Lord by satisfying Him fully, similarly one has to receive the transcendental knowledge from the spiritual master by satisfying him. The spiritual master's satisfaction is the means of assimilating transcendental knowledge. One cannot understand transcendental knowledge simply by becoming a grammarian. The Vedas declare (Śvetāśvatara Upaniṣad 6.23):
yasya deve parā bhaktir
yathā deve tathā gurau
tasyaite kathitā hy arthāḥ
prakāśante mahātmanaḥ
(ŚU 6.23)
"Only unto one who has unflinching devotion to the Lord and to the spiritual master does transcendental knowledge become automatically revealed." Such relationship between the disciple and the spiritual master is eternal. One who is now the disciple is the next spiritual master. And one cannot be a bona fide and authorized spiritual master unless one has been strictly obedient to his spiritual maste
(Srimad Bhagavatam-----2:9:43-----purport).

The mental speculators can reach the point of buddhi-yoga after many, many lifetimes of speculation, but the intelligent person who begins from the platform of intelligence above the mind makes rapid progress in self-realization. Because the buddhi-yoga process entails no fear of deterioration or retrogression at any time, it is the guaranteed path to self-realization, as confirmed in Bhagavad-gītā (2.40). The mental speculators cannot understand that the two birds (Śvetāśvatara Upaniṣad) sitting in one tree are the soul and the Supersoul. The individual soul eats the fruit of the tree, while the other bird does not eat the fruit but only observes the activities of the eating bird. Without attachment, the witnessing bird helps the fruit-eating bird perform fruitful activities. One who cannot understand this difference between the soul and the Supersoul, or God and the living entities, is certainly still in the entanglement of the cosmic machinery and thus must still await the time when he will be free from bondage.
(Srimad Bhagavatam-----2:6:9-----purport).

The demon used the word abhavāya, which means "for killing." Śrīdhara Svāmī comments that this "killing" means liberating, or, in other words, killing the process of continued birth and death. The Lord kills the process of birth and death and keeps Himself invisible. The activities of the Lord's internal potency are inconceivable, but by a slight exhibition of this potency, the Lord, by His grace, can deliver one from nescience. Śucaḥ means "miseries"; the miseries of material existence can be extinguished by the Lord by His potential energy of internal yogamāyā. In the Upaniṣads (Śvetāśvatara Upaniṣad 6.8) it is stated, parāsya śaktir vividhaiva śrūyate (Cc. Madhya 13.65, purport). The Lord is invisible to the eyes of the common man, but His energies act in various ways. When demons are in adversity, they think that God is hiding Himself and is working by His mystic potency. They think that if they can find God they can kill Him just by seeing Him. Hiraṇyākṣa thought that way, and he challenged the Lord: "You have done tremendous harm to our community, taking the part of the demigods, and You have killed our kinsmen in so many ways, always keeping Yourself hidden.
(Srimad Bhagavatam-----2:18:4-----purport)