Those who do not accept the Personality of Godhead, they are called Māyāvādīs. Māyāvādī means they see everything māyā. Even Kṛṣṇa is māyā. That is called Māyāvādī.
(Lecture on Bhagavad-Gita----7:1-3).

Even the Māyāvādī impersonalists, who flatter themselves that they have become the Lord, are not abhijña or svarāṭ, fully cognizant or fully independent. The Māyāvādī monists undergo a severe process of austerity and penance to acquire the knowledge needed for becoming one with the Lord, but ultimately they become dependent on some rich follower, who supplies them with requisite paraphernalia to construct great monasteries and temples.
(Teachings of Lord Caitanya).

Everything is born of the Supreme Brahman, from which everything emanates as different energies. None of these energies, therefore, should be considered false. The Māyāvādīs' differentiation between Brahman and māyā is only due to ignorance.
(Srimad Bhagavatam----8:12:8----purport).

Even according to historical references, Kṛṣṇa's activities are most uncommon. Kṛṣṇa has affirmed, "I am God," and He has acted accordingly. Māyāvādīs think that everyone can claim to be God, but that is their illusion, for no one else can perform such extraordinary activities as Kṛṣṇa.
(Sri Caitanya Caritamrta----1:3:87----purport).

Brahman spreads everywhere, but appreciation of Brahman in different objects leads to different results. In the Bhagavad-gītā the Lord says, ye yathā māṁ prapadyante tāṁs tathaiva bhajāmy aham: "I reward everyone according to his surrender unto Me." Māyāvādīs certainly realize Brahman in certain aspects, but realization of Brahman in the aspects of wine, women and meat is not the same realization of Brahman that devotees achieve by chanting, dancing and eating prasādam.
(Sri Caitanya Caritamrta----1:17:52----purport).

The Māyāvādīs proclaim that there is no separate existence outside the impersonal Brahman and that the feeling of separation is māyā, or an illusion, by which one considers a rope to be a snake. The rope-and-the-snake argument is generally offered by the Māyāvādī philosophers.
(Srimad Bhagavatam----4:22:38----purport).

The Māyāvādī philosophers say that the living entity and the Supreme Lord are nondifferent, and therefore they equate the transformation of the living entity with the transformation of the Lord. In other words, Māyāvādīs say that if the living entity is pleased, the Lord is also pleased, and if the living entity is displeased, the Lord is also displeased. By juggling words in this way, Māyāvādīs try to prove that there is no difference between the living entity and the Lord. This, however, is not a fact.
(Sri Caitanya Caritamrta----2:11:187----purport).

The Brahma-saṁhitā (5.29) describes that in the abode of Lord Kṛṣṇa, which is made of cintāmaṇi (touchstone), the Lord, acting as a cowherd boy, is served by hundreds and thousands of goddesses of fortune. Māyāvādīs think that the devotees have imagined the form of Kṛṣṇa, but the authentic Vedic scriptures have actually described Kṛṣṇa and His various transcendental forms.
(Sri Caitanya Caritamrta----1:3:111----purport).

The God of the monists, or Māyāvādīs, cannot eat, see, or hear. Such a concocted, formless God can never bring peace to the world. How can a God who has no sensory organs see the miseries of the people or hear their heartfelt prayers? To worship such a formless God in the name of searching for spiritual truth can only produce misfortune in the world, never good fortune.
(Renunciation Through Wisdom).

The Māyāvādīs are confused as to whether refuting the existence of consciousness or accepting it will give them contentment. The conscious beings always control inert matter. A simple example proves this point: we see how a puny conscious being like a crow defecates fearlessly on the head of a stone statue of some hero, thus demonstrating the conquest of dynamic spirit over dead matter. Only those with stonelike intelligence will try to make the supreme conscious being into an unfeeling, formless object. Such an attempt is utter foolishness.
(Renunciation Through Wisdom).

The Caitanya-caritāmṛta teaches that the spirit soul is immortal and that our activities in the spiritual world are also immortal. The Māyāvādīs, who hold the view that the Absolute is impersonal and formless, contend that a realized soul has no need to talk. But the Vaiṣṇavas, devotees of Kṛṣṇa, contend that when one reaches the stage of realization, he really begins to talk. "Previously we only talked of nonsense," the Vaiṣṇava says. "Now let us begin our real talks, talks of Kṛṣṇa." In support of their view that the self-realized remain silent, the Māyāvādīs are fond of using the example of the waterpot, maintaining that when a pot is not filled with water it makes a sound, but that when it is filled it makes no sound. But are we waterpots? How can we be compared to them? A good analogy utilizes as many similarities between two objects as possible. A waterpot is not an active living force, but we are. Ever-silent meditation may be adequate for a waterpot, but not for us. Indeed, when a devotee realizes how much he has to say about Kṛṣṇa, twenty-four hours in a day are not sufficient. It is the fool who is celebrated as long as he does not speak, for when he breaks his silence his lack of knowledge is exposed. The Caitanya-caritāmṛta shows that there are many wonderful things to discover by glorifying the Supreme.
(Sri Caitanya Caritamrta---introduction).

The Māyāvādīs' primary occupation is to offend the Supreme Personality of Godhead, Kṛṣṇa. For example, although Kṛṣṇa demands our surrender in the Bhagavad-gītā, the greatest scholar and so-called philosopher in modern India has protested that it is "not to Kṛṣṇa" that we have to surrender. Therefore, he is envious. Since Māyāvādīs of all different descriptions are envious of Kṛṣṇa, they have no scope for understanding the meaning of the Vedānta-sūtra.
(Sri Caitanya Caritamrta----1:7:144----purport).

Because the living entity is infinitesimal, he can be covered by an inferior energy. The foolishness and ignorance of the Māyāvādīs are revealed when they try to explain how the infinite can be covered by ignorance. It is offensive to attempt to qualify the infinite by arguing that He is subject to the spell of ignorance.
(Teachings of Lord Caitanya).

The very fact that the Māyāvādī claims to be one with the Supreme Lord means that he is not yet freed from the reactions of sinful activities.
(Krsna Book).

In this verse the word tyakṣyan is very significant in relation to Lord Śrī Kṛṣṇa's leaving His body. Since He is the eternal form of existence, knowledge and bliss, His body and His Self are identical. Therefore how is it possible that He would leave His body and then disappear from the vision of the world? There is a great controversy amongst the nondevotees or Māyāvādīs about the mysterious disappearance of the Lord, and the doubts of those men with a poor fund of knowledge have been very elaborately cleared by Śrīla Jīva Gosvāmī in his Kṛṣṇa-sandarbha.
(Srimad Bhagavatam----3:4:29----purport).

God is never made. God does not become. God is always God, not that one is not God, and he becomes God by some mystic yogic power. This theory is going on amongst the Māyāvādīs, that by the mystic yoga practice, one can become God. So we don't want such cheap God. They may become God, so-called God, but we are concerned with the real God, Kṛṣṇa.
( Lecture on Srimad Bhagavatam---1:10:2).

A Māyāvādī philosopher may falsely claim to be God or Kṛṣṇa, but he cannot actually act like Kṛṣṇa. He can persuade his followers to falsely imitate the rāsa dance, but he is unable to lift Govardhana Hill. We have many experiences in the past of Māyāvādī rascals who delude their followers by posing themselves as Kṛṣṇa in order to enjoy rāsa-līlā.
(Krsna Book).

This Māyāvāda viewpoint is always condemned by the Vaiṣṇava school. Śrī Caitanya Mahāprabhu Himself protested this philosophy. When the Māyāvādīs accept sannyāsa and consider themselves Nārāyaṇa, they become so puffed up that they do not even enter the temple of Nārāyaṇa to offer respects, for they falsely think themselves Nārāyaṇa Himself. Although Māyāvādī sannyāsīs may offer respects to other sannyāsīs and address them as Nārāyaṇa, they do not go to a Nārāyaṇa temple and offer respects. These Māyāvādī sannyāsīs are always condemned and are described as demons. The Vedas clearly state that living entities are subordinate parts and parcels of the supreme. Eko bahūnāṁ yo vidadhāti kāmān: the Supreme Being, Kṛṣṇa, maintains all living entities.
(Sri Caitanya Caritamrta----2:18:113----purport).