Materialistic scientists, puffed-up by the magical changes their so-called inventions have brought about, cannot see the real potency of Godhead behind matter. Therefore the jugglery of science is gradually leading people to a godless civilization at the cost of the goal of human life. Having missed the goal of life, materialists run after self-sufficiency, not knowing that material nature is already self-sufficient by the grace of God. Thus creating a colossal hoax in the name of civilization, they create an imbalance in the natural self-sufficiency of material nature.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Sri Chaitanya-charitamrita, Adi-lila 5.51, Purport

I offer my obeisances to Sri Chaitanya Mahaprabhu, by whose mercy even an ignorant child can swim across the ocean of conclusions about the ultimate truth, which is full of the crocodiles of various theories.
Srila Krishnadasa Kaviraja Goswami
Sri Chaitanya-charitamrita, Adi-lila 2.1

One who has accepted Me as the supreme goal of life should strictly observe the scriptural injunctions forbidding sinful activities and, as far as possible, should execute the injunctions prescribing minor regulative duties such as cleanliness. Ultimately, however, one should approach a bona fide spiritual master who is full in knowledge of Me as I am, who is peaceful, and who by spiritual elevation is not different from Me.
Lord Sri Krishna
Srimad-Bhagavatam 11.10.5

Persons who hear Srimad-Bhagavatam regularly and are always taking the matter very seriously will have the Personality of Godhead Sri Krishna manifested in their hearts within a short time.
Maharaja Parikshit
Srimad-Bhagavatam 2.8.4

Anyone whose work is not meant to elevate him to religious life, anyone whose religious ritualistic performances do not raise him to renunciation, and anyone situated in renunciation that does not lead him to devotional service to the Supreme Personality of Godhead, must be considered dead, although he is breathing.
Srimati Devahuti
Srimad-Bhagavatam 3.23.56

Renouncing all other goals, one should think, “Sri Sri Radha-Krishna are the only goal of my life.”
Lord Shiva
Sanat-kumara-samhita 126

Even a person who could count all the dust particles of the earth could not possibly enumerate the glory of Sri Vishnu.
Rig Veda 1.154.1

The Lord is beyond imperishable Brahman.
Mundaka Upanishad 2.1.2

Because worshipers have differences in knowledge, their perception of the Lord differs accordingly.
Vedanta-sutra 3.3.52

Krishna is established in truth, and truth is established in Him. Govinda is more true than truth itself, and so He has the name Truth.
Mahabharata, Udyoga-parva 68.12