The residents of both heaven and hell desire human birth on the earth planet because human life facilitates the achievement of transcendental knowledge and love of Godhead, whereas neither heavenly nor hellish bodies efficiently provide such opportunities. 
(Lord Sri Krsna, Srimad-Bhagavatam 11.20.12) 
T hose who are fortunate to receive the teachings of Lord Caitanya can progress very quickly. In a short life span, a person can easily progress from varnasrama to the highest level of prema, pure love of God. 
(Srila Bhaktivinoda Thakura, Sri Caitanya Siksamrta, Chapter 3, Part 1) 
The Personality of Godhead, Lord Krsna [Govinda] is the exclusive shelter for all great living beings, and His transcendental attri butes cannot even be measured by such masters of mystic powers as Lord Siva and Lord Brahma. Can anyone who is expert in relishing nectar [rasa) ever be fully satiated by hearing topics about Him? 
(Sages of Naimsaranya, Srimad-Bhagavatam 1.l8.14) 
Material enjoyments are full of poison , but you consider them pleasing. Do not think of them as a source of happiness, but understand them as distress. Be absorbed in full thought of Govinda, associate with His devotees, and conclude that devotional service is the goal of life. 
(Srila Narottama Dasa Thakura, Sri Prema Bhakti Candrika )
If you cannot purify yourself by any endeavor whatsoever, then just go sit with the Vaisnavas and you will achieve all auspiciousness. 
(Sri Ramanujacarya), (Quoted in Srila Bhaktivinoda Thakura's Bhaktyaloka)