The rishis of old attained the Knowledge of Brahman. One cannot have this so long as there is the slightest trace of worldliness. How hard the rishis laboured ! Early in the morning they would go away from the hermitage, and would spend the whole day in solitude, meditating on Brahman. At night they would return to the hermitage and eat a little fruit or roots. They kept their mind aloof from the objects of sight, hearing, touch, and other things of a worldly nature. Only thus did they realize Brahman as their own inner conciousness.
RamakrishnaOne cannot completely get rid of the six passions: lust, anger, greed, and the like. Therefore one should direct them to God. If you must have desire and greed, then you should desire love of God and be greedy to attain Him.
Ramakrishna