In material consciousness, the senses are engaged in sense gratification, but in Kṛṣṇa consciousness the senses are engaged in the satisfaction of Kṛṣṇa's senses. Therefore, the Kṛṣṇa conscious person is always free, even though he appears to be engaged in affairs of the senses.
(Bhagavad-Gita---5:8-9---purport).

The person in material consciousness is convinced by false ego that he is the doer of everything. He does not know that the mechanism of the body is produced by material nature, which works under the supervision of the Supreme Lord. The materialistic person has no knowledge that ultimately he is under the control of Kṛṣṇa.
(Bhagavad-Gita---3:27---purport).

Unless one is situated in Kṛṣṇa consciousness, his material consciousness will oblige him to transfer from one body to another because he has material desires since time immemorial. But he has to change that conception. That change can be effected only by hearing from authoritative sources.
(Bhagavad-Gita---13:22---purport).

Attachment cannot be killed; it has simply to be transferred. Attachment for material things is called material consciousness, and attachment for Kṛṣṇa or His devotee is called Kṛṣṇa consciousness. Consciousness, therefore, is the platform of attachment. It is clearly stated here that when we simply purify the consciousness from material consciousness to Kṛṣṇa consciousness, we attain liberation.
(Srimad Bhagavatam----3:25:20---purport).

Material consciousness is the cause of one's conditional life, in which conditions are enforced upon the living entity by the material energy. Although the spirit soul does not do anything and is transcendental to such activities, he is thus affected by conditional life.
(Srimad Bhagavatam---3:26:7---translation).

One should approach a Kṛṣṇa conscious person with all humility and put relevant questions to him. If one goes to challenge him, such a highly elevated Kṛṣṇa conscious person would not be available for any service. A challenging puffed-up person cannot gain anything from a Kṛṣṇa conscious man; he would simply remain inmaterial consciousness.
(Teachings of Lord Caitanya).

When a man sleeps, he dreams of many nonfactual happenings, and as a result of dreaming he becomes subject to different kinds of distress and happiness. Similarly, when a person is in the dream of material consciousness, he suffers the effects of accepting a body and giving it up again in material existence. Opposite to this material consciousness is Kṛṣṇa consciousness.
(Krsna Book),

If a particular part of the body is diseased, the whole attention of the body goes to that part. Similarly, devotees care for any person who is forgetful of Kṛṣṇa and therefore in material consciousness. The equal vision of the devotee is that he works to get all living entities back home, back to Godhead.
(Srimad Bhagavatam---4:7:53---purport).

Persons infatuated by material consciousness are very intelligent in discovering things for material comforts, but they have no access to understanding the spirit soul and spiritual life. Therefore, if anyone wants to advance in spiritual life, he has to come back to the platform of purified desire, the purified desire for devotional service.
(Srimad Bhagavatam---3:26:31---purport).