Only through devotional service can one understand how the Supreme Personality of Godhead, by His inconceivable potencies, simultaneously acts impersonally and as a person. He acts just like the supreme emperor, and many thousands of kings and chiefs work under Him. The Supreme Personality of Godhead is the supreme independent controlling person, and all the demigods, including Lord Brahmā, Lord Śiva, Indra (the King of heaven), the king of the moon planet and the king of the sun planet, work under His direction. The Vedas confirm that it is out of fear of the Supreme Personality of Godhead that the sun is shining, the wind is blowing, and fire is distributing heat. The material nature produces all kinds of movable and immovable objects within the material world, but none of them can independently act or create without the direction of the Supreme Lord. All of them act as His tributaries, just like subordinate kings who offer their annual taxes to the emperor.
The Vedic injunctions state that every living entity lives by eating the remnants of food offered to the Personality of Godhead. In great sacrifices the injunction is that Nārāyaṇa should be present as the supreme predominating Deity of the sacrifice and that after the sacrifice is performed the remnants of food should be distributed among the demigods. This is called yajña-bhāga. Every demigod has an allotment of yajña-bhāga, which he accepts as prasādam. The conclusion is that the demigods are not independently powerful: they are posted as different executives under the order of the Supreme Personality of Godhead, and they eat prasādam, or the remnants of sacrifices. They execute the order of the Supreme Lord exactly according to His plan. The Supreme Personality of Godhead is in the background, and because His orders are carried out by others, it appears that He is impersonal. In our grossly materialistic way, we cannot conceive how the Supreme Person is above the impersonal activities of material nature. Therefore the Lord explains in the Bhagavad-gītā that there is nothing superior to Him and that the impersonal Brahman is subordinately situated as a manifestation of His personal rays. Śrīpāda Śrīdhara Svāmī has composed a nice verse in this regard: "Let me offer my respectful obeisances unto the Supreme Personality of Godhead, who has no material senses but through whose direction and will all the material senses are working. He is the supreme potency of all material senses or sense organs. He is omnipotent, and He is the supreme performer of everything. Therefore He is worshipable by everyone. Unto that Supreme Person do I offer my respectful obeisances."
Kṛṣṇa Himself declares in the Bhagavad-gītā that because He is transcendental to all sentient and insentient beings He is known as Puruṣottama, which means the Supreme Personality. (Puruṣa means "person," and uttama means "supreme" or "transcendental.") In another place the Lord says that as the air is situated in the all-pervading sky, everyone is situated in Him, and everyone is acting under His direction.