kascid yatati siddhaye
yatatam api siddhanam
kascin mam vetti tattvatah
(Knowledge of the Absolute, Text 3 Chapter 7)
Out of many thousands among men, one may endeavor for perfection, and of those who have achieved perfection, hardly one knows Me in truth.
*** Only the pure devotees can know something of the inconceivable transcendental qualities in Krsna, in the cause of all causes, in his omnipotence and opulence, and in his Wealth, fame, strength, beauty, knowledge and renunciation.
Bhagavad Gita: Hardly one knows Me in Truth [Knowledge of the Absolute (Text 3 Chapter 7)]