What is night for all beings is the time of awakening for the self-controlled; and the time of awakening for all beings is night for the introspective sage.

Lord Sri Krsna
Bhagavad-gita 2.69

The servants of the Lord are actually the servants of society. … They are interested in imparting knowledge of the relationship of the living being with the Supreme Lord, the activities in that transcendental relationship, and the ultimate goal of human life. That is the real knowledge which can help society achieve the real aim of human welfare.

His Divine Grace A.C. Bhaktivedanta Swami Prabhupada
Srimad-Bhagavatam 3.4.25, Purport

Actual speech is that which describes the qualities of the Lord, real hands are those that work for Him, a true mind is that which always remembers Him dwelling within everything moving and nonmoving, and actual ears are those that listen to sanctifying topics about Him.

King Pariksit
Srimad-Bhagavatam 10.80.3

The impersonal Brahman is Lord Krsna's bodily effulgence. … As fireflies seem brilliant when the sun does not shine, so the impersonal Brahman is glorious only when Lord Krsna's form remains unseen.

Srila Bhaktivinoda Thakura
Kalyana-kalpataru 1.8.5

The son of Devaki, Krsna, is the Supreme Personality.

Narayana Upanisad 4

I worship the Personality of Godhead, Govinda [Krsna], who by one of His plenary portions enters every universe and every atom and thus unlimitedly manifests His infinite energy all over the material creation.

Lord Brahma
Brahma-samhita 5.35

Even the worms, birds, and beasts are assured of elevation to the highest perfected life if they are completely surrendered to the transcendental loving service of the Lord, so what to speak of the philosophers among the human beings.

Garuda Purana