The thirst for Krishna (God) is a sign of health in the spiritual field.  Not to have it is a sign of "Bhava Roga" - the disease that afflicts worldly persons, the symptoms being grief, discontent, pain and worry, even when health and wealth are endowed.  The thirst for God can be cultivated  by the reading of scriptures, the cultivation of congenial company, lessons from a kind and considerate Guru and regular practice of Japam.  Once it is acquired, the thirst itself will lead you on to places and persons able to quench it.  This is also the advantage of the spiritual quest; the first step makes the second easy.

- Sathya Sai Speaks,  Volume 6: 'Krishna Thrishna".