What is this world, creation, cosmic manifestation? Not only the material world; the spiritual world also. They are simply display of different energies of the Supreme Lord. Parāsya śaktir vividhaiva śrūyate (Śvetāśvatara Upaniṣad 6.8). Parāsya, "of the Supreme." He has got multi-energies, and they are divided into three principal categories: spiritual energy, material energy and marginal energy. The marginal energy is jīva. That is explained by Caitanya Mahāprabhu: kṛṣṇera "taṭasthā-śakti" "bhedābheda-prakāśa" (CC Madhya 20.108). I have given several times the example when we walk on the beach: the same land is sometimes covered with water, and sometimes there is no water. This is called taṭasthā. Sometimes with water; sometimes with no water. That is called taṭasthā. The water is one side, land is one side, and in the beach, between the water and the land, there is a marginal potency, or marginal place, where sometimes it is water, sometimes it is without water.
So jīva, being very small particle of the original fire, Kṛṣṇa, sometimes he is fall down. So when he falls down in the material world, he becomes extinguished of his spiritual energy. The same spark, it is in the fire, it is very beautiful, puff-puff, there is sparking. But as soon as the spark falls out of the fire, it is no more fire. Extinguished. Similarly, our position, being marginal, when we fall down from our Kṛṣṇa consciousness, that is our material life. And when you do not fall from Kṛṣṇa consciousness, that is our spiritual life. Anyone can understand very easily. Therefore taṭasthā-śakti, marginal. There is potency of falling down; therefore it is called taṭasthā. But when the jīva, or the spark, remains with the fire, there is no difference—both of them are fire. But when the jīva not remains with the fire, with Kṛṣṇa or Brahman or Paramātmā, then it becomes extinguished.