The desire to merge into the impersonal Brahman is the subtlest type of atheism. As soon as such atheism, disguised in the dress of liberation, is encouraged, one becomes completely unable to traverse the path of devotional service to the Supreme Personality of Godhead.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Sri Chaitanya-charitamrita, Adi 1.92, Purport

If we want to follow the path of true auspiciousness, we should give up the countless opinions of people and only hear the words of the Vedas.
Srila Bhaktisiddhanta Sarasvati Thakura
64 Principles for Community, Principle 13

Association with a devotee, the mercy of Krishna, and the nature of devotional service help one to give up all undesirable association and gradually attain elevation to the platform of love of Godhead.
Sri Chaitanya Mahaprabhu
Sri Chaitanya-charitamrita, Madhya 24.104

Simply by material birth, human beings become attached within their minds to personal sense gratification, long duration of life, sense activities, bodily strength, sexual potency, and friends and family. Their minds are thus absorbed in that which defeats their actual self-interest.
Lord Sri Krishna
Srimad-Bhagavatam 11.21.24

Therefore, my dear King, the living entity, who has a subtle mental covering, develops all kinds of thoughts and images because of his previous body. Take this from me as certain. There is no possibility of concocting anything mentally without having perceived it in the previous body.
Sri Narada Muni
Srimad-Bhagavatam 4.29.65

Caught in the grip of ignorance, self-proclaimed experts consider themselves learned authorities. They wander about this world befooled, like the blind leading the blind.
Katha Upanishad 1.2.5

The essence of all Vedic knowledge – comprehending the three kinds of Vedic activity [karma-kandajnana-kanda, and upasana-kanda], the chandas, or Vedic hymns, and the processes for satisfying the demigods – is included in the eight syllables Hare Krishna, Hare Krishna. This is the reality of all Vedanta. The chanting of the holy name is the only means to cross the ocean of nescience.
Narada Pancaratra
Quoted in Sri Chaitanya-charitamrita, Adi 7.76, Purport

Dearer to the Lord than even His own beautiful form, His easily worshiped holy name benefits the entire world. Indeed, nothing is as full of nectar as the holy name of the Lord.
The Vaikuntha-dutas
Sri Brihad-bhagavatamrita 2.3.184

A wise man who understands the Supreme falls in love with Him.
Brihad-aranyaka Upanishad 4.4.21