The human being is the elder brother of all other living beings. He is endowed with intelligence more powerful than animals for realizing the course of nature and the indications of the Almighty Father. Human civilizations should depend on the production of material nature without artificially attempting economic development to turn the world into a chaos of artificial greed and power only for the purpose of artificial luxuries and sense gratification. This is but the life of dogs and hogs.
His Divine Grace A. C. Bhaktivedanta Swami Prabhupada
Srimad-Bhagavatam 1.10.4, Purport

By being fixed in this knowledge, one can attain to the transcendental nature, which is like My own nature. Thus established, one is not born at the time of creation nor disturbed at the time of dissolution.
Lord Sri Krishna
Bhagavad-gita 14.2

Let me offer my respectful obeisances unto Him [Krishna] who is the associate of the members of the Yadu dynasty and who is always a problem for the nondevotees. He is the supreme enjoyer of both the material and spiritual worlds, yet He enjoys His own abode in the spiritual sky. There is no one equal to Him because His transcendental opulence is immeasurable.
Srila Shukadeva Goswami
Srimad-Bhagavatam 2.4.14

The Supreme Lord is full of eternity, knowledge and bliss. He is always embraced in the spiritual world by His divine energies called hladini (the ecstatic potency) and samvit (the omniscient potency). In the material world the individual soul (jiva) experiences many sufferings, being covered by his ignorance.
Quoted by Jiva Goswami in Bhagavat-sandarbha

Give up the company of evil persons, partake of the association of saintly persons, perform pious deeds both day and night, and remember always the flickering nature of the material world.
Chanakya Pandita

The propensity for selfish enjoyment deadens the pure function of the soul.
Srila Bhaktisiddhanta Sarasvati Thakura
Lecture, Vrindavana, Karttika 1928

Bhagavan is the one Supreme Being who expands all souls and all matter by His inconceivable energy (achintya-shakti) and then enters into these emanations as the Supreme Lord (ishvara-svarupa). He also transcends all souls and matter as the impersonal Brahman effulgence (brahma-svarupa), far beyond all imagination. He manifests His divine potency (para-shakti) to reveal His form of eternity, knowledge, and bliss (sach-chid-ananda-svarupa), thereby becoming the object of devotion for all souls.
Srila Bhaktivinoda Thakura
Vaishnava-siddhanta-mala, Chapter 2

Just as the minds of young girls take pleasure in young boys, and young boys take pleasure in young girls, kindly allow my mind to take pleasure in You [Krishna] alone.
Bhakti-rasamrita-sindhu 1.2.53