The mind is the original cause of material bondage. It is followed by many enemies, such as anger, pride, greed, lamentation, illusion and fear. The best way to control the mind is to engage it always in Kṛṣṇa consciousness (sa vai manaḥ kṛṣṇa-padāravindayoḥ (S.B.-9:4:18). Since the followers of the mind bring about material bondage, we should be very careful not to trust the mind.
(Srimad Bhagavatam---5:6:5--purport).

The descendants of Irreligion and Falsity, born one after another, are Bluffing, Cheating, Greed, Cunning, Anger, Envy, Quarrel, Harsh Speech, Death, Fear, Severe Pain and Hell. All these descendants are described as signs of devastation. If a person is pious and hears about these causes of devastation, he will feel hatred for all these, and that will cause his advancement in a life of piety. Piety refers to the process of cleansing the heart. As recommended by Lord Caitanya, one has to cleanse the dust from the mirror of the mind, and then advancement on the path of liberation begins. Here also the same process is recommended. Malam means: "contamination." We should learn to despise all the causes of devastation, beginning from irreligion and cheating, and then we shall be able to make advancement in a life of piety. The possibility of our attaining Kṛṣṇa consciousness will be easier, and we shall not be subjected to repeated devastation.
(Srimad Bhagavatam--4:8:5---purport).

There is one quality among the twenty qualities Kṛṣṇa lists that is especially noteworthy, and that is mayi cānanya-yogena bhaktir avyabhicāriṇī: "Constant and unalloyed devotion to Me (Kṛṣṇa)." The other qualities are required to cleanse the consciousness. Once the mirror of the mind is purified and the blazing fire of material existence extinguished, constant and unalloyed devotion to Lord Kṛṣṇa begins to appear on the horizon of the heart.
(Renunciation Through Wisdom).

The appearance of consciousness after the appearance of false ego indicates that, from the beginning, material consciousness is under the mode of ignorance and that one therefore has to purify himself by purifying his consciousness. This purificatory process is called Kṛṣṇa consciousness. As soon as the consciousness is purified, the false ego disappears. Identification of the body with the self is called false identification, or false ego. Lord Caitanya confirms this in His Śikṣāṣṭaka. He states that the first result of chanting the mahā-mantra, Hare Kṛṣṇa, is that dirt is cleared from the consciousness, or the mirror of the mind, and then at once the blazing fire of material existence is over. The blazing fire of material existence is due to false ego, but as soon as the false ego is removed, one can understand his real identity. At that point he is actually liberated from the clutches of māyā. As soon as one is freed from the clutches of false ego, his intelligence also becomes purified, and then his mind is always engaged upon the lotus feet of the Supreme Personality of Godhead.
(Srimad Bhagavatam--3:26:61---purport).

That the Lord is not formless is experienced by Nārada Muni. But His form is completely different from all forms of our material experience. For the whole duration of our life we go see different forms in the material world, but none of them is just apt to satisfy the mind, nor can any one of them vanish all perturbance of the mind. These are the special features of the transcendental form of the Lord, and one who has once seen that form is not satisfied with anything else; no form in the material world can any longer satisfy the seer. That the Lord is formless or impersonal means that He has nothing like a material form and is not like any material personality.
(Srimad Bhagavatam-1:6:18---purport).