Lord Krsna is very much pleased with His devotees, even if they are not on the topmost stage of devotional service. Even on the lower stages of devotional service one is transcendental, and if one continues with devotional life, he continues to be a deva or sura [godly person]. If one continues in this way, Krsna will always be pleased with him and will give him all instructions so that he may very easily return home, back to Godhead.

His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Srimad-Bhagavatam 8.5.24, Purport

If one becomes a bookworm, reading many books and scriptures and hearing many commentaries and the instructions of many men, this will produce doubt within his heart. One cannot in this way ascertain the goal of life.

Srila Krsnadasa Kaviraja Gosvami
Sri Caitanya-caritamrta, Adi-lila 16.11

I continually glorified the Lord and meditated upon Him for millions of years, and at last I was able to understand the transcendental form of the Lord as Sri Krsna, in the dress of a cowherd boy.

Lord Brahma
Sri Gopala-tapani Upanisad 1.27

Even if a great genius could somehow or other, after a time-consuming effort, count all the particles of dust on the surface of the earth, such a genius could never count the attractive qualities of the Personality of Godhead, who is the reservoir of all potencies.

Sri Drumila
Srimad-Bhagavatam 11.4.2

The holy name of Lord Krsna is the sweetest of all sweetnesses and the most auspicious of all auspiciousness. It is completely spiritual, and it is the transcendental fruit of all Vedic literature. If an ordinary human being chants the holy name of Krsna even only once with faith, or even in the spirit of mocking Him, the holy name will deliver the chanter from the bondage of repeated birth and death.

Skanda Purana, Prabhasa-khanda
(Quoted in Jiva Gosvami's Tattva-sandarbha, 15.4)

No knowledge is a pure as the holy name of the Lord. No vow is as powerful as the holy name. No meditation in the world is like the holy name. No philosophy brings a result like the holy name. No renunciation is greater than the holy name. Nothing will ever be equal to the holy name.

Srila Haridasa Thakura
Sri Hari-nama-cintamani 8.4-6