Therefore in the Bhagavad-gita there is the essence of Vedic instructions. The plan is that the conditioned soul may fulfill his desire for material enjoyment and at the same time be trained up in spiritual identity to come back to Godhead, back to home. As such, Bhagavad-gita contains the solution of all problems of the material world.
Letter to Dr. Ghosh, 29 March, 1974