SB 5.20.3-4

śivaṁ yavasaṁ subhadraṁ śāntaṁ kṣemam amṛtam abhayam iti varṣāṇi teṣu girayo nadyaś ca saptaivābhijñātāḥ; maṇikūṭo vajrakūṭa indraseno jyotiṣmān suparṇo hiraṇyaṣṭhīvo meghamāla iti setu-śailāḥ aruṇā nṛmṇāṅgirasī sāvitrī suptabhātā ṛtambharā satyambharā iti mahā-nadyaḥ; yāsāṁ jalopasparśana-vidhūta-rajas-tamaso haṁsa-pataṅgordhvāyana-satyāṅga-saṁjñāś catvāro varṇāḥ sahasrāyuṣo vibudhopama-sandarśana-prajananāḥ svarga-dvāraṁ trayyā vidyayā bhagavantaṁ trayīmayaṁ sūryam ātmānaṁ yajante.
Synonyms: 
śivam — Śiva; yavasam — Yavasa; subhadram — Subhadra; śāntam — Śānta; kṣemam — Kṣema; amṛtam — Amṛta; abhayam — Abhaya; iti — thus; varṣāṇi — the tracts of land according to the names of the seven sons; teṣu — in them; girayaḥ — mountains; nadyaḥ ca — and rivers; sapta — seven; eva — indeed; abhijñātāḥ — are known; maṇi-kūṭaḥ — Maṇikūṭa; vajra-kūṭaḥ — Vajrakūṭa; indra-senaḥ — Indrasena; jyotiṣmān — Jyotiṣmān; suparṇaḥ — Suparṇa; hiraṇya-ṣṭhīvaḥ — Hiraṇyaṣṭhīva; megha-mālaḥ — Meghamāla; iti — thus; setu-śailāḥ — the ranges of mountains marking the borders of the varṣas; aruṇā — Aruṇā; nṛmṇā — Nṛmṇā; āṅgirasī — Āṅgirasī; sāvitrī — Sāvitrī; supta-bhātā — Suptabhātā; ṛtambharā — Ṛtambharā; satyambharā — Satyambharā; iti — thus; mahā-nadyaḥ — very large rivers; yāsām — of which; jala-upasparśana — simply by touching the water; vidhūta — washed off; rajaḥ-tamasaḥ — whose modes of passion and ignorance; haṁsa — Haṁsa; pataṅga — Pataṅga; ūrdhvāyana — Ūrdhvāyana; satyāṅga — Satyāṅga; saṁjñāḥ — named; catvāraḥ — four; varṇāḥ — castes or divisions of men; sahasra-āyuṣaḥ — living for one thousand years; vibudha-upama — similar to the demigods; sandarśana — in having very beautiful forms; prajananāḥ — and in producing children; svarga-dvāram — the gateway to the heavenly planets; trayyā vidyayā — by performing ritualistic ceremonies according to Vedic principles; bhagavantam — the Supreme Personality of Godhead; trayī-mayam — established in the Vedas; sūryam ātmānam — the Supersoul, represented by the sun-god; yajante — they worship.
Translation: 
The seven islands [varṣas] are named according to the names of those seven sons — Śiva, Yavasa, Subhadra, Śānta, Kṣema, Amṛta and Abhaya. In those seven tracts of land, there are seven mountains and seven rivers. The mountains are named Maṇikūṭa, Vajrakūṭa, Indrasena, Jyotiṣmān, Suparṇa, Hiraṇyaṣṭhīva and Meghamāla, and the rivers are named Aruṇā, Nṛmṇā, Āṅgirasī, Sāvitrī, Suptabhātā, Ṛtambharā and Satyambharā. One can immediately be free from material contamination by touching or bathing in those rivers, and the four castes of people who live in Plakṣadvīpa — the Haṁsas, Pataṅgas, Ūrdhvāyanas and Satyāṅgas — purify themselves in that way. The inhabitants of Plakṣadvīpa live for one thousand years. They are beautiful like the demigods, and they also beget children like the demigods. By completely performing the ritualistic ceremonies mentioned in the Vedas and by worshiping the Supreme Personality of Godhead as represented by the sun-god, they attain the sun, which is a heavenly planet.
Purport: 

According to general understanding, there are originally three deities — Lord Brahmā, Lord Viṣṇu and Lord Śiva — and people with a poor fund of knowledge consider Lord Viṣṇu no better than Lord Brahmā or Lord Śiva. This conclusion, however, is invalid. As stated in the Vedas, iṣṭāpūrtaṁ bahudhā jāyamānaṁ viśvaṁ bibharti bhuvanasya nābhiḥ tad evāgnis tad vāyus tat sūryas tad u candramāḥ agniḥ sarvadaivataḥ. This means that the Supreme Lord, who accepts and enjoys the results of Vedic ritualistic ceremonies (technically called iṣṭāpūrta), who maintains the entire creation, who supplies the necessities of all living entities (eko bahūnāṁ yo vidadhāti kāmān) and who is the central point of all creation, is Lord Viṣṇu. Lord Viṣṇu expands as the demigods known as Agni, Vāyu, Sūrya and Candra, who are simply parts and parcels of His body. Lord Kṛṣṇa says in Śrīmad Bhagavad-gītā (9.23):

ye ’py anya-devatā-bhaktā
 yajante śraddhayānvitāḥ
te ’pi mām eva kaunteya
 yajanty avidhi-pūrvakam

“Devotees who worship the demigods with firm faith worship Me also, but not according to regulative principles.” In other words, if one worships the demigods but does not understand the relationship between the demigods and the Supreme Personality of Godhead, his worship is irregular. Kṛṣṇa also says in Bhagavad-gītā (9.24), ahaṁ hi sarva-yajñānāṁ bhoktā ca prabhur eva ca: “I am the only enjoyer of ritualistic ceremonies.”

It may be argued that the demigods are as important as Lord Viṣṇu because the names of the demigods are different names of Viṣṇu. This, however, is not a sound conclusion, for it is contradicted in the Vedic literatures. The Vedas declare:

candramā manaso jātaś cakṣoḥ sūryo ajāyata; śrotrādayaś ca prāṇaś ca mukhād agnir ajāyata; nārāyaṇād brahmā, nārāyaṇād rudro jāyate, nārāyaṇāt prajāpatiḥ jāyate, nārāyaṇād indro jāyate, nārāyaṇād aṣṭau vasavo jāyante, nārāyaṇād ekādaśa rudrā jāyante.

“The demigod of the moon, Candra, came from the mind of Nārāyaṇa, and the sun-god came from His eyes. The controlling deities of hearing and the life air came from Nārāyaṇa, and the controlling deity of fire was generated from His mouth. Prajāpati, Lord Brahmā, came from Nārāyaṇa, Indra came from Nārāyaṇa, and the eight Vasus, the eleven expansions of Lord Śiva and the twelve Ādityas also came from Nārāyaṇa.” In the smṛti Vedic literature it is also said:

brahmā śambhus tathaivārkaś
 candramāś ca śatakratuḥ
evam ādyās tathaivānye
 yuktā vaiṣṇava-tejasā

jagat-kāryāvasāne tu
 viyujyante ca tejasā
vitejaś ca te sarve
 pañcatvam upayānti te

“Brahmā, Śambhu, Sūrya and Indra are all merely products of the power of the Supreme Personality of Godhead. This is also true of the many other demigods whose names are not mentioned here. When the cosmic manifestation is annihilated, these different expansions of Nārāyaṇa’s potencies will merge into Nārāyaṇa. In other words, all these demigods will die. Their living force will be withdrawn, and they will merge into Nārāyaṇa.”

Therefore it should be concluded that Lord Viṣṇu, not Lord Brahmā or Lord Śiva, is the Supreme Personality of Godhead. As a government officer is sometimes accepted as the entire government although he is actually but a departmental manager, so the demigods, having achieved power of attorney from Viṣṇu, act on His behalf, although they are not as powerful as He. All the demigods must work under the orders of Viṣṇu. Therefore it is said, ekale īśvara kṛṣṇa, āra saba bhṛtya. The only master is Lord Kṛṣṇa, or Lord Viṣṇu, and all others are His obedient servants, who act exactly according to His orders. The distinction between Lord Viṣṇu and the demigods is also expressed in Bhagavad-gītā (9.25).

yānti deva-vratā devān
 pitṝn yānti pitṛ-vratāḥ
bhūtāni yānti bhūtejyā
 yānti mad-yājino ’pi mām

Those who worship the demigods go to the planets of the demigods, whereas the worshipers of Lord Kṛṣṇa and Lord Viṣṇu go to the planets in Vaikuṇṭha. These are the statements of the smṛti. Therefore the idea that Lord Viṣṇu is on the same level as the demigods is in contradiction to the śāstras. The demigods are not supreme. The supremacy of the demigods is dependent on the mercy of Lord Nārāyaṇa (Viṣṇu, or Kṛṣṇa).