Isvarah paramah krsnah. The Supreme God is one-Krsna-and the demigods are delegated with powers to manage this material world. These demigods are all living entities (nityanam) with different grades of material power. BG 1972 purports

Expressions researched:
"The Supreme God is one—Krsna—and the demigods are delegated with powers to manage this material world. These demigods are all living entities (nityanam) with different grades of material power"

BG Chapters 1 - 6

The Supreme God is one—Kṛṣṇa—and the demigods are delegated with powers to manage this material world. These demigods are all living entities with different grades of material power.

BG 4.12, Translation and Purport:

Men in this world desire success in fruitive activities, and therefore they worship the demigods. Quickly, of course, men get results from fruitive work in this world.

There is a great misconception about the gods or demigods of this material world, and men of less intelligence, although passing as great scholars, take these demigods to be various forms of the Supreme Lord. Actually, the demigods are not different forms of God, but they are God's different parts and parcels. God is one, and the parts and parcels are many. The Vedas say, nityo nityānām: God is one. Īśvaraḥ paramaḥ kṛṣṇaḥ. The Supreme God is one—Kṛṣṇa—and the demigods are delegated with powers to manage this material world. These demigods are all living entities (nityānām) with different grades of material power. They cannot be equal to the Supreme God—Nārāyaṇa, Viṣṇu, or Kṛṣṇa. Anyone who thinks that God and the demigods are on the same level is called an atheist, or pāṣaṇḍī. Even the great demigods like Brahmā and Śiva cannot be compared to the Supreme Lord. In fact, the Lord is worshiped by demigods such as Brahmā and Śiva (śiva-viriñci-nutam (SB 11.5.33)). Yet curiously enough there are many human leaders who are worshiped by foolish men under the misunderstanding of anthropomorphism or zoomorphism. Iha devatāḥ denotes a powerful man or demigod of this material world. But Nārāyaṇa, Viṣṇu, or Kṛṣṇa, the Supreme Personality of Godhead, does not belong to this world. He is above, or transcendental to, material creation. Even Śrīpāda Śaṅkarācārya, the leader of the impersonalists, maintains that Nārāyaṇa, or Kṛṣṇa, is beyond this material creation. However, foolish people (hṛta-jñāna (BG 7.20)) worship the demigods because they want immediate results. They get the results, but do not know that results so obtained are temporary and are meant for less intelligent persons. The intelligent person is in Kṛṣṇa consciousness, and he has no need to worship the paltry demigods for some immediate, temporary benefit. The demigods of this material world, as well as their worshipers, will vanish with the annihilation of this material world.