SB 1.3 - The need for creation
The creation and destruction of the material world is done by the supreme will because of the nitya-baddha living beings. These souls have the sense of individuality or ahaṅkāra, which dictates them sense enjoyment. The eternally conditioned souls, forgetful of its constitutional position as the enjoyed, have strong aspirations to enjoy. The chance to enjoy matter is given to the conditioned souls in the material world, and side by side they are given the chance to understand their real constitutional position. Those souls who do not surrender to Lord Vāsudeva are merged into the mahat-tattva at the time of annihilation of the material creation. When creation begins again, this mahat-tattva is let loose. This mahat-tattva contains all the ingredients of the material manifestations, including the conditioned souls. Primarily this mahat-tattva is divided into 16 parts, namely the five gross elements, and the eleven working instruments or senses. The mahat-tattva is assembled in some corner of the vast spiritual sky, and the part of the spiritual sky thus covered by the mahat-tattva is called the material sky. Within this mahat-tattva there are innumerable universes, which are produced by the Kāraṇodakaśāyī Viṣṇu, who simply throws His glance to impregnate the material sky.
In each and every universe the puruṣa enters as the Garbhodakaśāyī Viṣṇu. He lies down within the half of the universe which is full with the water of His body. And from His navel, springs a stem of the lotus flower atop which Brahmā becomes manifest. Within the stem of the lotus there are 14 divisions of planetary systems, and the earthly planets are situated in the middle. Upwards there are better planetary systems, and the topmost is called Brahmaloka or Satyaloka. Downwards from the earthly system there are seven lower planetary systems inhabited by the asuras and similar other beings.