Māyā, or illusion, is the condition of spiritual life contaminated by material infection. Liberation from this material infection does not mean destruction of the original eternal position of the living entity. (Bhagavad-Gita--6:20-23--purport).

Those who do not know Kṛṣṇa are in illusion, and so knowledge of Kṛṣṇa is liberation, and ignorance of Him is bondage.
(Bhagavad-Gita--7:8--purport).

And that happiness which is blind to self-realization, which is delusion from beginning to end and which arises from sleep, laziness and illusion is said to be of the nature of ignorance.
One who takes pleasure in laziness and in sleep is certainly in the mode of darkness, ignorance, and one who has no idea how to act and how not to act is also in the mode of ignorance. For the person in the mode of ignorance, everything is illusion. There is no happiness either in the beginning or at the end. For the person in the mode of passion there might be some kind of ephemeral happiness in the beginning and at the end distress, but for the person in the mode of ignorance there is only distress both in the beginning and at the end.
(Bhagavad-Gita--18:39--translation and purport).

By the influence of darkness, the conditioned soul forgets his relationship with the Supreme Lord and is overwhelmed by attachment, hatred, pride, ignorance and false identification, the five kinds of illusion that cause material bondage. (Srimad Bhagavatam--3:10:17--purport).

Everyone who is not in Kṛṣṇa consciousness must be considered to be in illusion. One's so-called feelings of happiness and satisfaction resulting from material things are also illusions. Factually neither society, friendship, love nor anything else can save one from the onslaught of the external energy, which is symptomized by birth, death, old age and disease.
(Srimad Bhagavatam--4:25:55--purport).

The mind is the cause of both material bondage and liberation. The impure mind thinks, "I am this body." The pure mind knows that he is not the material body; therefore the mind is considered to be the root of all material designations. Until the living entity is aloof from the association and contaminations of this material world, the mind will be absorbed in such material things as birth, death, disease, illusion, attachment, greed and enmity. In this way the living entity is conditioned, and he suffers material miseries.
(Srimad Bhagavatam--5:11:16--purport).

We transmigrate from one body to another in bodies that are products of our illusion, but as spirit souls we always exist separately from material, conditional life. The example given here is that a house or car is always different from its owner, but because of attachment the conditioned soul thinks it to be identical with him. A car or house is actually made of material elements; as long as the material elements combine together properly, the car or house exists, and when they are disassembled the house or the car is disassembled. The spirit soul, however, always remains as he is. (Srimad Bhagavatam--7:2:42--purport).

"Kṛṣṇa is compared to sunshine, and māyā is compared to darkness. Wherever there is sunshine, there cannot be darkness. As soon as one takes to Kṛṣṇa consciousness, the darkness of illusion, the influence of the external energy, will immediately vanish." (Nectar of Instruction).

The child cries to have the moon from the mother, and the mother gives the child a mirror to satisfy the crying and disturbing child with the reflection of the moon. Similarly, the crying child of the Lord is given over to the reflection, the material world, to lord it over as karmī and to give this up in frustration to become one with the Lord. Both these stages are dreaming illusions only. There is no necessity of tracing out the history of when the living entity desired this. But the fact is that as soon as he desired it, he was put under the control of ātma-māyā by the direction of the Lord. Therefore the living entity in his material condition is dreaming falsely that this is "mine" and this is "I." The dream is that the conditioned soul thinks of his material body as "I" or falsely thinks that he is the Lord and that everything in connection with that material body is "mine." Thus only in dream does the misconception of "I" and "mine" persist life after life. This continues life after life, as long as the living entity is not purely conscious of his identity as the subordinate part and parcel of the Lord.
(Srimad Bhagavatam--2:9:1--purport).

Misconceiving one thing for another thing is called illusion. For example, accepting a rope as a snake is illusion, but the rope is not false. The rope, as it exists in the front of the illusioned person, is not at all false, but the acceptance is illusory. Therefore the wrong conception of accepting this material manifestation as being divorced from the energy of the Lord is illusion, but it is not false. And this illusory conception is called the reflection of the reality in the darkness of ignorance. Anything that appears as apparently not being "produced out of My energy" is called māyā. The conception that the living entity is formless or that the Supreme Lord is formless is also illusion.
(Srimad Bhagavatam--2:9:34--purport).