The ambition to corroborate the existence of the transcendental Absolute Truth by limited conjectural endeavors cannot be fulfilled, because He is beyond the scope of our limited speculative minds. In an honest search for truth, we must admit that His powers are inconceivable to our tiny brains.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Sri Chaitanya-charitamrita, Adi-lila 2.96, Purport

Sing the glories of Krishna. Glorify Krishna, worship Krishna, and chant the name of Krishna. Do not think of anything other than Krishna. If you have any affection for Me, then don’t speak about any topics other than Krishna. Whether you are sleeping, eating, or waking, day and night think of Krishna and chant His name.
Sri Chaitanya Mahaprabhu
Sri Chaitanya-bhagavata, Madhya-khanda 28.25?28

One who does not desire anything within this world, who has achieved peace by controlling his senses, whose consciousness is equal in all conditions, and whose mind is completely satisfied in Me finds only happiness wherever he goes.
Lord Sri Krishna
Srimad-Bhagavatam 11.14.13

By constant truthfulness, transcendental knowledge, and austerity, one becomes eligible to associate with the Supreme Personality of Godhead.
Mundaka Upanishad 3.1.5

Those who are less intelligent accept the Vedic ritualistic ceremonies as all in all. They do not know that the purpose of the Vedas is to understand one’s own home, where the Supreme Personality of Godhead lives. Not being interested in their real home, they are illusioned and search after other homes.
Sri Narada Muni
Srimad-Bhagavatam 4.29.48

How much power does the name of Krsna possess? My heart constantly burns in the fire of worldly desires, like a desert scorched by the sun. The holy name, entering within my heart through the holes of my ears, showers unparalleled nectar upon my soul.
Srila Bhaktivinoda Thakura
Krishna Nama Dhare Kota Bal, Verse 1

O Lord Krishna, accompanied by Your dear associates You are splendidly manifested in Your eternally blissful abode, which bears the name Vraja. How merciful are You? We cannot understand how merciful. We cannot understand. Rejecting everything else, we choose only You. In this way we will become pure in heart.
Srila Jiva Goswami
Yam Sriman Vraja Raja Sindhuja, Verse 9

In the Vedic literature, including the Ramayana, Puranas, and Mahabharata, from the very beginning to the end, as well as within the middle, only Hari, the Supreme Personality of Godhead, is explained.
Hari-vamsha, Bhavishyat-parva 132.95