Factually, the Lord is not formless, nor does He belong to any of the multiforms experienced within the universal forms. One should try to know the truth about the Lord by following the instruction of Brahmaji
SB Canto 2
I myself (Brahmā), Lord Śiva, Lord Viṣṇu, great generators of living beings like Dakṣa and Prajāpati, yourselves (Nārada and the Kumāras), heavenly demigods like Indra and Candra, the leaders of the Bhūrloka planets, the leaders of the earthly planets, the leaders of the lower planets, the leaders of the Gandharva planets, the leaders of the Vidyādhara planets, the leaders of the Cāraṇaloka planets, the leaders of the Yakṣas, Rakṣas and Uragas, the great sages, the great demons, the great atheists and the great spacemen, as well as the dead bodies, evil spirits, satans, jinn, kūṣmāṇḍas, great aquatics, great beasts and great birds, etc.—in other words, anything and everything which is exceptionally possessed of power, opulence, mental and perceptual dexterity, strength, forgiveness, beauty, modesty, opulence, and breeding, whether in form or formless—may appear to be the specific truth and the form of the Lord, but actually they are not so. They are only a fragment of the transcendental potency of the Lord.
Those in the list given above, beginning from the name Brahmājī, the first living creature within the universe, down to Lord Śiva, Lord Viṣṇu, Nārada and other powerful demigods, men, supermen, sages, ṛṣis, and other lower creatures of extraordinary strength and opulence, including the dead bodies, satans, evil spirits, jinn, aquatics, birds and beasts, may appear to be the Supreme Lord, but factually none of them is the Supreme Lord; every one of them possesses only a fragment of the great potencies of the Supreme Lord. The less intelligent man is surprised to see the wonderful actions of material phenomena, as the aborigines are fearful of a great thunderbolt, a great and gigantic banyan tree, or a great lofty mountain in the jungle. For such undeveloped human beings, merely the slight display of the Lord's potency is captivating. A still more advanced person is captivated by the powers of the demigods and goddesses. Therefore, those who are simply astonished by the powers of anything in the creation of the Lord, without any factual information of the Lord Himself, are known as śāktas, or worshipers of the great powers. The modern scientist is also captivated by the wonderful actions and reactions of natural phenomena and therefore is also a śākta. These lower-grade persons gradually rise to become saurīyas (worshipers of the sun-god) or gāṇapatyas (worshipers of the mass of people as janatā janārdana or daridra-nārāyaṇa, etc., in the form of Gaṇapati) and then rise to the platform of worshiping Lord Śiva in search for the ever-existing soul, and then to the stage of worshiping Lord Viṣṇu, the Supersoul, etc., without any information of Govinda, Lord Kṛṣṇa, who is the original Lord Viṣṇu. In other ways some are worshipers of race, nationality, birds, beasts, evil spirits, satans, etc. The general worship of Śanideva, the lord of distressful condition, and Sītalādevī, the goddess of smallpox, is also common to the mass of people, and there are many foolish men who worship the mass of people or the poor class of men. So different persons, societies and communities, etc., worship some of the potent manifestations of the Lord, wrongly accepting the powerful object as God. But in this verse it is advised by Brahmājī that none of them is the Supreme Lord; they are only borrowed plumes from the original Almighty Lord Śrī Kṛṣṇa. When the Lord advises in Bhagavad-gītā to worship Him alone, it is to be understood that worshiping Lord Kṛṣṇa includes worshiping all that is mentioned, because He, Lord Kṛṣṇa, includes everyone.
When the Lord is described as formless in the Vedic literatures, it is to be understood that all these forms mentioned above, within the experience of universal knowledge, are different exhibitions of the Lord's transcendental potencies only, and none of them factually represents the transcendental form of the Lord. But when the Lord actually descends on the earth or anywhere within the universe, the less intelligent class of men also mistake Him to be one of them, and thus they imagine the Transcendence to be formless or impersonal. Factually, the Lord is not formless, nor does He belong to any of the multiforms experienced within the universal forms. One should try to know the truth about the Lord by following the instruction of Brahmājī.