Both material nature and the living entity are eternal. That is to say that they existed before the creation. The material manifestation is from the energy of the Supreme Lord, and so also are the living entities, but the living entities are of the superior energy. Both the living entities and material nature existed before this cosmos was manifested. Material nature was absorbed in the Supreme Personality of Godhead, Mahā-Viṣṇu, and when it was required, it was manifested by the agency of mahat-tattva.
(Bhagavad-Gita-----13:20-----purport).

Both material nature and the living entity, which were existing before the creation of the cosmos, are explained in this verse. Whatever is created is but a combination of the living entity and material nature. There are many manifestations like trees, mountains and hills which are not moving, and there are many existences which are moving, and all of them are but combinations of material nature and the superior nature, the living entity. Without the touch of the superior nature, the living entity, nothing can grow. The relationship between material nature and spiritual nature is eternally going on, and this combination is effected by the Supreme Lord; therefore He is the controller of both the superior and inferior natures. The material nature is created by Him, and the superior nature is placed in this material nature, and thus all these activities and manifestations take place.
(Bhagavad-Gita-----13:27-----purport).

There are two types of dissolution of the manifested cosmos. At the end of every 4,320,000,000 solar years, when Brahmā, the lord of one particular universe, goes to sleep, there is one annihilation. And at the end of Lord Brahmā's life, which takes place at the end of Brahmā's one hundred years of age, in our calculation at the end of 8,640,000,000 x 30 x 12 x 100 solar years, there is complete annihilation of the entire universe, and in both the periods both the material energy called the mahat-tattva and the marginal energy called jīva-tattva merge in the person of the Supreme Lord. The living beings remain asleep within the body of the Lord until there is another creation of the material world, and that is the way of the creation, maintenance and annihilation of the material manifestation.
(Srimad Bhagavatam-----1:10:21-----purport).

The great elements of material creation, namely earth, water, fire, air and ether, all enter into the body of all manifested entities—the seas, mountains, aquatics, plants, reptiles, birds, beasts, human beings, demigods and everyone materially manifested—and at the same time such elements are differently situated. In the developed stage of consciousness, the human being can study both physiological and physical science, but the basic principles of such sciences are nothing but the material elements and nothing more. The body of the human being and the body of the mountain, as also the bodies of the demigods, including Brahmā, are all of the same ingredients—earth, water, etc.—and at the same time the elements are beyond the body. The elements were created first, and therefore they entered into the bodily construction later, but in both circumstances they entered the cosmos and also did not enter. Similarly, the Supreme Lord, by His different energies, namely the internal and external, is within everything in the manifested cosmos, and at the same time He is outside of everything, situated in the kingdom of God (Vaikuṇṭhaloka) as described before.
(Srimad Bhagavatam-----2:9:35-----purport).

The material nature, known as māyā, is both the material and efficient cause of the cosmos, but in the background the Lord is the consciousness for all activities. As in the individual body the consciousness is the source of all energies of the body, so the supreme consciousness of the Lord is the source of all energies in material nature.
(Srimad Bhagavatam-----3:5:25-----purport).

Two words used in this verse are sat and asat. The cosmic manifestation is asat—it does not exist—but the material energy of the Supreme Lord is sat, or ever existing. Material nature is ever existing in its subtle form as the energy of the Lord, but it sometimes manifests this nonexistent or temporarily existent nature, the cosmos. An analogy may be made with the father and mother: the mother and the father exist, but sometimes the mother begets children. Similarly, this cosmic manifestation, which comes from the unmanifest material nature of the Supreme Lord, sometimes appears and again disappears. But the material nature is ever existing, and the Lord is the supreme cause for both the subtle and gross manifestations of this material world.
(Srimad Bhagavatam-----3:26:9-----purport).

Yet despite the creation, maintenance and destruction of the cosmos, the Lord is not affected. The various activities of the Lord must be very disturbing to the tiny living entities, but since the Lord is supremely great, He is never affected. Lord Śiva or any other pure devotee can see this clearly without being blinded by bheda-buddhi, or differentiation. For a devotee, the Lord is the supreme spirit soul. Since He is supremely powerful, His various powers are also spiritual. For a devotee, there is nothing material, for material existence only means forgetfulness of the Supreme Personality of Godhead.
(Srimad Bhagavatam-----4:24:61-----purport).

My dear Lord, Your Lordship alone is the cause and the effect. Therefore, although You appear to be two, You are the absolute one. As there is no difference between the gold of a golden ornament and the gold in a mine, there is no difference between cause and effect; both of them are the same. Only because of ignorance do people concoct differences and dualities. You are free from material contamination, and since the entire cosmos is caused by You and cannot exist without You, it is an effect of Your transcendental qualities. Thus the conception that Brahman is true and the world false cannot be maintained. (Srimad Bhagavatam-----8:12:8-----purport).

The mahat-tattva, the total material energy, is undivided, but because of the material modes of nature, it appears to separate into earth, water, fire, air and ether. Because of the living energy (jīva-bhūta), these separated energies combine to make the cosmic manifestation visible, but in fact, before the creation of the cosmos, the total energy is already present. Therefore, the total material energy never actually enters the creation. Similarly, although You are perceived by our senses because of Your presence, You cannot be perceived by the senses, nor experienced by the mind or words (avāṅ-mānasa-gocara). With our senses we can perceive some things, but not everything; for example, we can use our eyes to see, but not to taste. Consequently, You are beyond perception by the senses. Although in touch with the modes of material nature, You are unaffected by them. You are the prime factor in everything, the all-pervading, undivided Supersoul. For You, therefore, there is no external or internal. You never entered the womb of Devakī; rather, You existed there already.
(Srimad Bhagavatam-----10:3:15-17-----translation).

The three puruṣas—Kāraṇodakaśāyī Viṣṇu, Garbhodakaśāyī Viṣṇu and Kṣīrodakaśāyī Viṣṇu—all have a relationship with the material energy, called māyā, because through māyā They create the material cosmos. These three puruṣas, who lie on the Kāraṇa, Garbha and Kṣīra oceans respectively, are the Supersoul of everything that be: Kāraṇodakaśāyī Viṣṇu is the Supersoul of the collective universes, Garbhodakaśāyī Viṣṇu is the Supersoul of the collective living beings, and Kṣīrodakaśāyī Viṣṇu is the Supersoul of all individual living entities. Because all of Them are somehow attracted to the affairs of the material energy, They can be said to have some affection for māyā. But the transcendental position of Śrī Kṛṣṇa Himself is not even slightly tinged by māyā. His transcendental state is called turīya, or the fourth-dimensional stage.
(Sri Caitanya Caritamrta-----1:2:52-----purport).

The Absolute Truth is therefore the substance of reality, eternally manifest in three energies. The manifestation of the internal energy of the Lord is the inconceivably variegated spiritual world, the manifestation of the marginal energy comprises the living entities, and the manifestation of the external energy is the material cosmos. Therefore the Absolute Truth includes these four principles—the Supreme Personality of Godhead Himself, His internal energy, His marginal energy and His external energy. The form of the Lord and the expansions of His form as svayaṁ-rūpa and vaibhava-prakāśa are directly the enjoyers of the internal energy, which is the eternal exhibitor of the spiritual world, the most confidential of the manifestations of energy.
(Sri Caitanya Caritamrta-----1:4:62-----purport).

Kṛṣṇa is always all-spiritual. Aside from the parents of the Personality of Godhead, all the other paraphernalia of His existence are also essentially a manifestation of sandhinī-śakti, or a transformation of viśuddha-sattva. To make this more clear, it may be said that this sandhinī-śakti of the internal potency maintains and manifests all the variegatedness of the spiritual world. In the kingdom of God, the Lord's servants and maidservants, His consorts, His father and mother and everything else are all transformations of the spiritual existence of sandhinī-śakti. The existential sandhinī-śakti in the external potency similarly expands all the variegatedness of the material cosmos, from which we can have a glimpse of the spiritual field.
(Sri Caitanya Caritamrta-----1:4:65-----purport).

There are two kinds of research to find the original cause of creation. One conclusion is that the Supreme Personality of Godhead, the all-blissful, eternal, all knowing form, is indirectly the cause of this cosmic manifestation and directly the cause of the spiritual world, where there are innumerable spiritual planets known as Vaikuṇṭhas, as well as His personal abode, known as Goloka Vṛndāvana. In other words, there are two manifestations—the material cosmos and the spiritual world. As in the material world there are innumerable planets and universes, so in the spiritual world there are also innumerable spiritual planets and universes, including the Vaikuṇṭhas and Goloka. The Supreme Lord is the cause of both the material and spiritual worlds. The other conclusion, of course, is that this cosmic manifestation is caused by an inexplicable unmanifested void. This argument is meaningless.
(Sri Caitanya Caritamrta-----1:6:14-15-----purport).

One who chants oṁkāra no longer remains a śūdra but immediately comes to the position of a brāhmaṇa. Simply by chanting oṁkāra one can understand the whole creation to be one unit, or an expansion of the energy of the Supreme Lord: idaṁ hi viśvaṁ bhagavān ivetaro yato jagat-sthāna-nirodha-sambhavāḥ. "The Supreme Lord Personality of Godhead is Himself this cosmos, and still He is aloof from it. From Him only this cosmic manifestation has emanated, in Him it rests, and unto Him it enters after annihilation." (S.B.1:5:20) Although one who does not understand concludes otherwise, Śrīmad-Bhāgavatam states that the entire cosmic manifestation is but an expansion of the energy of the Supreme Lord. Realization of this is possible simply by chanting the holy name of the Lord, oṁkāra.
(Sri Caitanya Caritamrta-----1:7:128-----purport).

The living entities are factually beyond this covered, inferior energy. They have their pure spiritual existence, their pure identity and their pure mental activities—all beyond the manifestation of this material cosmos. Although the living entity's mind, intelligence and identity are beyond the range of this material world, when he enters into this material world due to his desire to lord it over matter, his original mind, intelligence and body become covered by the material energy. When he is again free of the covering of this material, inferior energy, he is called liberated. When he is liberated he has no false ego, but his real ego again comes into existence.
(Teachings of Lord Caitanya).