One who disbelieves in the shastras is an atheist, and we should not consult an atheist, however great he may be. A staunch believer in the shastras, with all their diversities, is the right person from whom to gather real knowledge. Such knowledge may seem inconceivable in the beginning, but when put forward by the proper authority its meaning is revealed, and then one no longer has any doubts about it.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Sri Chaitanya-charitamrita, Adi-lila 5.14, Purport

The soul’s propensity is not to enjoy matter or even to renounce it. There is no “give me, give me” in the spirit soul’s nature. The soul is the associated counterpart of the Absolute Truth, Vishnu. The soul’s only self-interest is to desire happiness for the Absolute Truth. Pure Vaishnavas always search with heart and soul after what will make the Absolute Truth happy.
Srila Bhaktisiddhanta Sarasvati Thakura
Uncommon Conversations, Conversation 7

My dear Uddhava, an intelligent person should never take to literatures that do not contain descriptions of My activities, which purify the whole universe. Indeed, I create, maintain, and annihilate the entire material manifestation. Among all My pastime incarnations, the most beloved are Krishna and Balarama. Any so-called knowledge that does not recognize these activities of Mine is simply barren and is not acceptable to those who are actually intelligent.
Lord Sri Krishna
Srimad-Bhagavatam 11.11.20

Of the different processes recommended for disentanglement from material life, the one personally explained and accepted by the Supreme Personality of Godhead should be considered all-perfect. That process is the performance of duties by which love for the Supreme Lord develops.
Sri Prahlada Maharaja
Srimad-Bhagavatam 7.7.29

A person who has transcendental knowledge as his charioteer and who carefully holds the reins of the mind reaches the end of the path: the transcendental realm of Lord Vishnu.
Katha Upanishad 1.3.9

With intellect purified by faith, and with all sincerity, please worship Krishna, an ocean of good qualities, who is the acme of transcendental glory, and who purifies those who purify others. How wonderful! Just by rising in one’s heart, even the semblance of His name destroys the heap of grievous sins, just as the dawn dispels all darkness.
Padma Purana
Quoted in Bhakti-rasamrita-sindhu 2.1.103

Honor the Bhagavatam and other scriptures that tell of this devotional service. Hear from them regularly about the Lord’s pastimes. For when those narrations enter the holes of your ears and you relish them with love, they will swiftly award you the Lord’s abode.
Sri Brihad-bhagavatamrita 2.3.124