Even the devotees of the Personality of Godhead are not annihilated during the period of the entire annihilation of the material world, not to speak of the Lord Himself. The Lord is ever-existent in all three stages of material change.
The impersonalist adduces no activity in the Supreme, but in this discussion between Brahmā and the Supreme Personality of Godhead the Lord is said to have activities also, as He has His form and quality. The activities of Brahmā and other demigods during the maintenance of the creation are to be understood as the activities of the Lord. The king, or the head executive of a state, may not be seen in the government offices, for he may be engaged in royal comforts. Yet it should be understood that everything is being done under his direction and everything is at his command. The Personality of Godhead is never formless. In the material world He may not be visible in His personal form to the less intelligent class of men, and therefore He may sometimes be called formless. But actually He is always in His eternal form in His Vaikuṇṭha planets as well as in other planets of the universes as different incarnations. The example of the sun is very appropriate in this connection. The sun in the night may not be visible to the eyes of men in the darkness, but the sun is visible wherever it has risen. That the sun is not visible to the eyes of the inhabitants of a particular part of the earth does not mean that the sun has no form.
In the Bṛhad-āraṇyaka Upaniṣad (1.4.1) there is the hymn ātmaivedam agra āsīt puruṣa-vidhaḥ. This mantra indicates the Supreme Personality of Godhead (Kṛṣṇa) even before the appearance of the puruṣa incarnation. In the Bhagavad-gītā (BG 15.18) it is said that Lord Kṛṣṇa is Puruṣottama because He is the supreme puruṣa, transcendental even to the puruṣa-akṣara and the puruṣa-kṣara. The akṣara-puruṣa, or the Mahā-Viṣṇu, throws His glance over prakṛti, or material nature, but the Puruṣottama existed even before that. The Bṛhad-āraṇyaka Upaniṣad therefore confirms the statement of the Bhagavad-gītā that Lord Kṛṣṇa is the Supreme Person (Puruṣottama).